$67+ Cheap flights from San Diego (SAN) to Boulder, CO
This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 7/8. Fares are subject to change and may not be available on all flights or dates of travel.
SAN — DEN
Jul 5 — Jul 121
Round-trip
1 adult, Economy
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Find cheap flights from San Diego to Boulder with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheapflights Tip: The best prices from San Diego to Boulder are usually found in February or January, booked 63 days in advance, depart on a Friday or Saturday and return on a Thursday
Cheap flight deals from San Diego to Boulder
Cheapest
Best
Last-minute
One-way
Cheapest flights from San Diego to BoulderExplore the most affordable flight options available from San Diego to Boulder. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 5, 2026.
Explore the most affordable flight options available from San Diego to Boulder. Find the lowest fares from popular airlines and budget airlines, with prices last updated on June 5, 2026.
This Cheapflightsfares deal was found by Cheapflights users on 6/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/156:25 am
SAN
- DEN
Nonstop2h 33m
Frontier
Sun 10/1810:32 pm
DEN
- SAN
Nonstop2h 27m
Frontier
Deal found 6/1![Frontier logo]()
$106
This Super.com deal was found by Cheapflights users on 6/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 9/1810:36 am
SAN
- DEN
Nonstop2h 32m
Frontier
Sun 9/2010:32 pm
DEN
- SAN
Nonstop2h 27m
Frontier
Deal found 6/1![Frontier logo]()
$107
This Frontier deal was found by Cheapflights users on 6/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/106:25 am
SAN
- DEN
Nonstop2h 33m
Frontier
Mon 9/148:10 am
DEN
- SAN
Nonstop2h 31m
Frontier
Deal found 6/1![Frontier logo]()
$108
This Cheapflightsfares deal was found by Cheapflights users on 6/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/246:25 am
SAN
- DEN
Nonstop2h 38m
Frontier
Wed 7/2910:29 pm
DEN
- SAN
Nonstop2h 22m
Frontier
Deal found 6/3![Frontier logo]()
$122
This Frontier deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/106:25 am
SAN
- DEN
Nonstop2h 38m
Frontier
Wed 8/1210:29 pm
DEN
- SAN
Nonstop2h 22m
Frontier
Deal found 6/4![Frontier logo]()
$123
This Frontier deal was found by Cheapflights users on 6/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/296:25 am
SAN
- DEN
Nonstop2h 33m
Frontier
Wed 9/302:12 pm
DEN
- SAN
Nonstop2h 29m
Frontier
Deal found 6/2![Frontier logo]()
$125
This Cheapflightsfares deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/296:25 am
SAN
- DEN
Nonstop2h 38m
Frontier
Sun 8/27:40 am
DEN
- SAN
Nonstop2h 25m
Frontier
Deal found 6/4![Frontier logo]()
$127
This Cheapflightsfares deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/16:25 am
SAN
- DEN
Nonstop2h 41m
Frontier
Thu 7/307:40 am
DEN
- SAN
Nonstop2h 25m
Frontier
Deal found 6/4![Frontier logo]()
$128
This Frontier deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/96:25 am
SAN
- DEN
Nonstop2h 38m
Frontier
Wed 8/127:45 am
DEN
- SAN
Nonstop2h 25m
Frontier
Deal found 6/4![Frontier logo]()
$129
This Cheapflightsfares deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/26:25 am
SAN
- DEN
Nonstop2h 38m
Frontier
Thu 8/610:29 pm
DEN
- SAN
Nonstop2h 22m
Frontier
Deal found 6/4![Frontier logo]()
$130
This Super.com deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/246:25 am
SAN
- DEN
Nonstop2h 38m
Frontier
Mon 8/310:29 pm
DEN
- SAN
Nonstop2h 22m
Frontier
Deal found 6/4![Frontier logo]()
$131
Best flights from San Diego to BoulderDiscover carefully curated flight deals from San Diego to Boulder that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated June 5, 2026.
Discover carefully curated flight deals from San Diego to Boulder that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated June 5, 2026.
This Delta deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/231:36 pm
SAN
- DEN
1 stop4h 54m
Delta
Thu 9/245:56 pm
DEN
- SAN
1 stop6h 56m
Delta
Deal found 6/4![Delta logo]()
$207
This Southwest deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/312:55 pm
SAN
- DEN
1 stop3h 50m
Southwest
Fri 7/104:55 pm
DEN
- SAN
Nonstop2h 25m
Southwest
Deal found 6/5![Southwest logo]()
$303
This Delta deal was found by Cheapflights users on 5/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/101:30 pm
SAN
- DEN
1 stop4h 40m
Delta
Mon 9/145:30 am
DEN
- SAN
1 stop4h 11m
Delta
Deal found 5/31![Delta logo]()
$217
This Southwest deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/232:40 pm
SAN
- DEN
2 stops7h 25m
Southwest
Sat 6/2711:05 am
DEN
- SAN
1 stop4h 40m
Southwest
Deal found 6/5![Southwest logo]()
$373
This Delta deal was found by Cheapflights users on 6/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/166:15 am
SAN
- DEN
1 stop4h 38m
Delta
Tue 6/237:00 pm
DEN
- SAN
1 stop5h 53m
Delta
Deal found 6/2![Delta logo]()
$342
This Southwest deal was found by Cheapflights users on 6/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/212:40 pm
SAN
- DEN
2 stops7h 30m
Southwest
Thu 7/238:30 am
DEN
- SAN
1 stop3h 50m
Southwest
Deal found 6/2![Southwest logo]()
$378
This Southwest deal was found by Cheapflights users on 6/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/212:40 pm
SAN
- DEN
2 stops7h 30m
Southwest
Fri 7/2411:00 am
DEN
- SAN
1 stop4h 45m
Southwest
Deal found 6/2![Southwest logo]()
$378
This Delta deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/206:15 am
SAN
- DEN
1 stop4h 38m
Delta
Mon 6/227:50 pm
DEN
- SAN
1 stop4h 50m
Delta
Deal found 6/4![Delta logo]()
$397
This Southwest deal was found by Cheapflights users on 6/1. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/248:00 am
SAN
- DEN
1 stop4h 45m
Southwest
Sun 7/267:50 am
DEN
- SAN
2 stops6h 40m
Southwest
Deal found 6/1![Southwest logo]()
$654
This Delta deal was found by Cheapflights users on 5/31. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/2810:00 am
SAN
- DEN
1 stop7h 10m
Delta
Sun 11/112:45 pm
DEN
- SAN
2 stops11h 10m
Delta
Deal found 5/31![Delta logo]()
$755
Last-minute flights from San Diego to BoulderDiscover last-minute flight deals from San Diego to Boulder. Data last updated June 5, 2026 and is based on user searches.
Discover last-minute flight deals from San Diego to Boulder. Data last updated June 5, 2026 and is based on user searches.
This Frontier deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/236:25 am
SAN
- DEN
Nonstop2h 41m
Frontier
Tue 6/307:40 am
DEN
- SAN
Nonstop2h 29m
Frontier
Deal found 6/4![Frontier logo]()
$152
This Cheapflightsfares deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/3010:04 am
SAN
- DEN
Nonstop2h 33m
Frontier
Wed 7/17:40 am
DEN
- SAN
Nonstop2h 29m
Frontier
Deal found 6/4![Frontier logo]()
$147
This Cheapflightsfares deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/16:25 am
SAN
- DEN
Nonstop2h 41m
Frontier
Thu 7/307:40 am
DEN
- SAN
Nonstop2h 25m
Frontier
Deal found 6/4![Frontier logo]()
$128
This Cheapflightsfares deal was found by Cheapflights users on 6/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/1410:00 am
SAN
- DEN
Nonstop2h 41m
Frontier
Tue 7/2110:29 pm
DEN
- SAN
Nonstop2h 22m
Frontier
Deal found 6/3![Frontier logo]()
$134
This Kiwi.com deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/153:03 pm
SAN
- DEN
1 stop5h 38m
Frontier
Wed 7/297:40 am
DEN
- SAN
Nonstop2h 25m
Frontier
Deal found 6/4![Frontier logo]()
$148
This Kiwi.com deal was found by Cheapflights users on 6/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/223:03 pm
SAN
- DEN
1 stop5h 38m
Frontier
Wed 7/2910:29 pm
DEN
- SAN
Nonstop2h 22m
Frontier
Deal found 6/3![Frontier logo]()
$135
This Cheapflightsfares deal was found by Cheapflights users on 6/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/246:25 am
SAN
- DEN
Nonstop2h 38m
Frontier
Wed 7/2910:29 pm
DEN
- SAN
Nonstop2h 22m
Frontier
Deal found 6/3![Frontier logo]()
$122
This Super.com deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/246:25 am
SAN
- DEN
Nonstop2h 38m
Frontier
Mon 8/310:29 pm
DEN
- SAN
Nonstop2h 22m
Frontier
Deal found 6/4![Frontier logo]()
$131
This Cheapflightsfares deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/296:25 am
SAN
- DEN
Nonstop2h 38m
Frontier
Sun 8/27:40 am
DEN
- SAN
Nonstop2h 25m
Frontier
Deal found 6/4![Frontier logo]()
$127
This Cheapflightsfares deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/306:25 am
SAN
- DEN
Nonstop2h 38m
Frontier
Sun 8/27:40 am
DEN
- SAN
Nonstop2h 25m
Frontier
Deal found 6/4![Frontier logo]()
$136
This Kiwi.com deal was found by Cheapflights users on 6/2. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/306:25 am
SAN
- DEN
Nonstop2h 38m
Frontier
Tue 8/410:00 am
DEN
- SAN
1 stop5h 08m
Frontier
Deal found 6/2![Frontier logo]()
$149
One-way flights from San Diego to BoulderSearch for one-way flight options from San Diego to Boulder. Find affordable one-way fares based on user searches. Data last updated June 5, 2026.
Search for one-way flight options from San Diego to Boulder. Find affordable one-way fares based on user searches. Data last updated June 5, 2026.
This Super.com deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/810:00 am
SAN
- DEN
Nonstop2h 41m
Frontier
Deal found 6/4![Frontier logo]()
$67
This Frontier deal was found by Cheapflights users on 6/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/76:25 am
SAN
- DEN
Nonstop2h 38m
Frontier
Deal found 6/3![Frontier logo]()
$68
This Kiwi.com deal was found by Cheapflights users on 6/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/24:17 pm
SAN
- DEN
1 stop4h 29m
Frontier
Deal found 6/3![Frontier logo]()
$77
This Kiwi.com deal was found by Cheapflights users on 6/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/294:17 pm
SAN
- DEN
1 stop23h 53m
Frontier
Deal found 6/3![Frontier logo]()
$79
This Frontier deal was found by Cheapflights users on 6/3. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 6/246:25 am
SAN
- DEN
Nonstop2h 41m
Frontier
Deal found 6/3![Frontier logo]()
$81
This Super.com deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 8/1710:10 am
SAN
- DEN
Nonstop2h 41m
Frontier
Deal found 6/4![Frontier logo]()
$82
This Super.com deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/236:25 am
SAN
- DEN
Nonstop2h 41m
Frontier
Deal found 6/5![Frontier logo]()
$83
This Super.com deal was found by Cheapflights users on 6/4. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 7/236:25 am
SAN
- DEN
Nonstop2h 38m
Frontier
Deal found 6/4![Frontier logo]()
$88
This Frontier deal was found by Cheapflights users on 6/5. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 7/56:25 am
SAN
- DEN
Nonstop2h 38m
Frontier
Deal found 6/5![Frontier logo]()
$89
Find flight deals from San Diego to Boulder
Keep the following information in mind while searching for San Diego to Boulder flight deals. Data was last updated June 5, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $106 (Cheapflightsfares) |
One-way from | $67 (Super.com) |
Popular in | June |
Cheapest in | February |
Average price | $254 |
Cheapflights Fare Finder
Customize your flight search to find flights from San Diego to Boulder that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 5, 2026.
Use the filters below to find and compare flights from San Diego to Boulder that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
San DiegoDenver
SAN - DEN
SANDEN
San Diego
Wed 9/23
1:36 pm-7:30 pm
1 stop4h 54m
Denver Intl
Thu 9/24
5:56 pm-11:52 pm
1 stop6h 56m
$207
San DiegoDenver
SAN - DEN
SANDEN
San Diego
Thu 9/10
1:30 pm-7:10 pm
1 stop4h 40m
Denver Intl
Mon 9/14
5:30 am-8:41 am
1 stop4h 11m
$217
Quickest round-trip
San DiegoDenver
SAN - DEN
SANDEN
San Diego
Fri 7/3
12:55 pm-5:45 pm
1 stop3h 50m
Denver Intl
Fri 7/10
4:55 pm-6:20 pm
Nonstop2h 25m
$303
San DiegoDenver
SAN - DEN
SANDEN
San Diego
Tue 6/16
6:15 am-11:53 am
1 stop4h 38m
Denver Intl
Tue 6/23
7:00 pm-11:53 pm
1 stop5h 53m
$342
San DiegoDenver
SAN - DEN
SANDEN
San Diego
Tue 6/23
2:40 pm-11:05 pm
2 stops7h 25m
Denver Intl
Sat 6/27
11:05 am-2:45 pm
1 stop4h 40m
$373
San DiegoDenver
SAN - DEN
SANDEN
San Diego
Tue 7/21
2:40 pm-11:10 pm
2 stops7h 30m
Denver Intl
Thu 7/23
8:30 am-11:20 am
1 stop3h 50m
$378
San DiegoDenver
SAN - DEN
SANDEN
San Diego
Tue 7/21
2:40 pm-11:10 pm
2 stops7h 30m
Denver Intl
Fri 7/24
11:00 am-2:45 pm
1 stop4h 45m
$378
San DiegoDenver
SAN - DEN
SANDEN
San Diego
Sat 6/20
6:15 am-11:53 am
1 stop4h 38m
Denver Intl
Mon 6/22
7:50 pm-11:40 pm
1 stop4h 50m
$397
San DiegoDenver
SAN - DEN
SANDEN
San Diego
Fri 7/24
8:00 am-1:45 pm
1 stop4h 45m
Denver Intl
Sun 7/26
7:50 am-1:30 pm
2 stops6h 40m
$654
San DiegoDenver
SAN - DEN
SANDEN
San Diego
Wed 10/28
10:00 am-6:10 pm
1 stop7h 10m
Denver Intl
Sun 11/1
12:45 pm-10:55 pm
2 stops11h 10m
$755
Showing 1-10 of 22 resultsSorted by cheapest first
Best time to book a flight from San Diego to Boulder
Have a flexible travel schedule? Discover the best time to fly to Boulder from San Diego with our price prediction graph.
SAN-DEN
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.
Cheapflights Insights
Everything you need to know about your flight from San Diego to Boulder
SAN-BD9
SAN-DEN
What is the cheapest time of day to fly from SAN to BD9?
Find hourly flight availability from San Diego to Boulder. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated June 5, 2026.
A simple way to save on the total cost of your ticket is to fly from San Diego to Boulder in the evening. If you’re flexible enough to do this you can expect to save up to 33% on your trip compared to booking a flight in the afternoon.
Weekly flight availability from San Diego to Boulder
Explore weekly flight availability from San Diego to Boulder. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated June 5, 2026.
The most flights from SAN to BD9 are scheduled on a Friday (33 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (12 on average).
How much does it cost to fly round-trip from San Diego to Boulder?
What is the cheapest day to fly from San Diego to Boulder?
Use this chart to determine the cheapest time to fly round-trip from San Diego to Boulder. Price data was last updated on May 30, 2026.
Travelers seeking maximum savings on their San Diego to Boulder flight should consider departing on Tuesday at noon when fares are most often at their lowest. Tuesday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.
Reviews of airlines servicing Boulder
Get insights into the airlines that provide service to Boulder. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Boulder. Reviews last updated June 5, 2026.
See what other customers who have flown with Southwest,Alaska Airlines, andHawaiian Airlines from San Diego to Boulder have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Food
7.0
Overall
8.0
Comfort
8.0
Crew
8.6
Boarding
8.1
Entertainment
7.5
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Food
7.0
Overall
8.0
Comfort
8.0
Crew
8.6
Boarding
8.1
Entertainment
7.5
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Food
7.0
Overall
8.0
Comfort
8.0
Crew
8.6
Boarding
8.1
Entertainment
7.5
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Food
7.0
Overall
8.0
Comfort
8.0
Crew
8.6
Boarding
8.1
Entertainment
7.5
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Food
7.0
Overall
8.0
Comfort
8.0
Crew
8.6
Boarding
8.1
Entertainment
7.5
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Food
7.0
Overall
8.0
Comfort
8.0
Crew
8.6
Boarding
8.1
Entertainment
7.5
Reviews
1 / 20
8.0
ExcellentLa Tracimeldamarcos,Jun 2026
LAX - SLC
Related info for your journey
Find useful and relevant information for your journey from San Diego to Boulder. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
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San Diego and Boulder flights
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Other flights from San Diego
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Top 5 airlines flying from San Diego to Boulder
Discover the top 5 airlines that operate flights from San Diego to Boulder. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated June 5, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$50 | Average$149 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$68 | Average$167 | FlexibilityNo cancel fee | On-time85% | |
| Cheapest$111 | Average$203 | FlexibilityNo cancel fee | On-time75% | |
| Cheapest$117 | Average$285 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$117 | Average$321 | FlexibilityNo cancel fee | On-time69% |