HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Portsmouth

$262+ Cheap flights from Riverside, CA to Portsmouth, England

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 10/19. Fares are subject to change and may not be available on all flights or dates of travel.
LAX — LHR
Aug 5 — Aug 121
Tue 8/5
Tue 8/12
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Riverside to Portsmouth 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.

Cheap flight deals from Riverside to Portsmouth

Keep the following information in mind while searching for Riverside to Portsmouth flight deals. Data was last updated July 31, 2025.

Round-trip from

$841
(Delta)

One-way from

$262
(Kiwi.com)

Popular in

January

Cheapest in

February

Average price

$1,327
From Riverside to Portsmouth
Search Deals
One-way flight from Riverside to Portsmouth
Search Deals
Highest demand for flights based on searches. 11% potential increase in price ($149 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($51 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in July 2025
Search Deals

Find flight deals from Riverside to Portsmouth

Cheapest flights from Riverside to Portsmouth
Explore the most affordable flight options available from Riverside to Portsmouth. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 31, 2025.

This Expedia deal was found by Cheapflights users on 7/28. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 9/78:15 pmLAX - SOU
1 stop15h 15mAer Lingus
Mon 9/159:40 amSOU - LAX
1 stop16h 45mAer Lingus
Deal found 7/28$821
This KLM deal was found by Cheapflights users on 7/29. 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 KLM is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/104:50 pmLAX - SOU
1 stop16h 10mKLM
Wed 9/179:20 amSOU - LAX
1 stop34h 30mKLM
Deal found 7/29$841
This Delta deal was found by Cheapflights users on 7/28. 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 9/34:50 pmLAX - SOU
1 stop31h 55mDelta
Mon 9/155:35 pmSOU - LAX
1 stop26h 15mDelta
Deal found 7/28$843

Cheapflights Fare Finder

 
Customize your flight search to find flights from Riverside to Portsmouth 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 July 31, 2025.
Use the filters below to find and compare flights from Riverside to Portsmouth that are best for you.

Fly from

Riverside

Fly to

Portsmouth

Route

Depart

Return

Price

Los AngelesSouthampton

LAX - SOU

LAXSOU

Los Angeles

Sun 9/7

8:15 pm-7:30 pm

1 stop15h 15m

Southampton Eastleigh

Mon 9/15

9:40 am-6:25 pm

1 stop16h 45m

$821

Los AngelesSouthampton

LAX - SOU

LAXSOU

Los Angeles

Wed 9/10

4:50 pm-8:45 am

1 stop31h 55m

Southampton Eastleigh

Mon 9/22

5:35 pm-2:50 pm

1 stop29h 15m

$841

Los AngelesSouthampton

LAX - SOU

LAXSOU

Los Angeles

Fri 9/26

1:50 pm-8:45 am

1 stop34h 55m

Southampton Eastleigh

Wed 10/15

9:20 am-11:50 am

1 stop34h 30m

$890

Los AngelesSouthampton

LAX - SOU

LAXSOU

Los Angeles

Sun 10/19

4:30 pm-8:15 am

2 stops31h 45m

$262

Los AngelesSouthampton

LAX - SOU

LAXSOU

Los Angeles

Sun 10/19

8:15 pm-8:15 am

1 stop28h 00m

$441

Los AngelesSouthampton

LAX - SOU

LAXSOU

Los Angeles

Wed 8/13

4:45 pm-8:45 am

1 stop32h 00m

$514

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/29

Best time to book a flight from Riverside to Portsmouth

Have a flexible travel schedule? Discover the best time to fly to Portsmouth from Riverside with our price prediction graph.
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 Riverside to Portsmouth

What is the cheapest month to book a flight from Riverside to Portsmouth?

Currently, November is the cheapest month in which you can book a flight from Riverside to Portsmouth (average of $661). Flying from Riverside to Portsmouth in June is currently the most expensive (average of $1,097). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from R1V to P0R?

Find hourly flight availability from Riverside to Portsmouth. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated July 31, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Riverside to Portsmouth as you normally would.

What is the cheapest day to fly from Riverside to Portsmouth?

Use this chart to determine the cheapest time to fly round-trip from Riverside to Portsmouth. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Riverside to Portsmouth flight should consider departing on Tuesday evenings when fares are most often at their lowest. Thursday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Riverside to Portsmouth

Explore weekly flight availability from Riverside to Portsmouth. 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 July 31, 2025.

The most flights from R1V to P0R are scheduled on a Monday (59 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (44 on average).

Reviews of airlines servicing Portsmouth

Get insights into the airlines that provide service to Portsmouth. 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 Portsmouth. Reviews last updated July 31, 2025.
Peruse reviews from past customers who have flown with Delta, KLM, and Aer Lingus from Riverside to Portsmouth to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
7,981 reviews

Food

7.3

Entertainment

7.9

Comfort

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
Delta
8.0
Very good
7,981 reviews
Delta
8.0
Very good
7,981 reviews

Food

7.3

Entertainment

7.9

Comfort

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
KLM
7.8
Good
1,383 reviews
Delta
8.0
Very good
7,981 reviews

Food

7.3

Entertainment

7.9

Comfort

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.
Aer Lingus
7.1
Good
1,192 reviews
Delta
8.0
Very good
7,981 reviews

Food

7.3

Entertainment

7.9

Comfort

7.9

Boarding

8.2

Crew

8.5

Overall

8.0

Reviews

1 / 20
10.0
Excellent

Aaron,Oct 2024

LAX - LHR

This was a flight operated by Virgin Atlantic in their Upper Class cabin. Overall, an outstanding experience.

Related info for your journey

Find useful and relevant information for your journey from Riverside to Portsmouth. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What are the most reliable airlines from Riverside to Portsmouth?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Riverside to Portsmouth on time: KLM (89%), Air France (89%), Delta (89%).

  • What are the cheapest flights from Riverside to Portsmouth?

    On average you can expect to pay $3,320 for a flight from Riverside to Portsmouth. The cheapest flight overall is $377 while the most popular route, (Los Angeles - Southampton Eastleigh) is currently priced at $821.

  • Can I find deals for flights from Riverside to Portsmouth that include hotel bookings?

    Yes. In addition to deals on Riverside to Portsmouth flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Riverside to Portsmouth?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Riverside to Portsmouth.

  • Can I find deals for business class flights from Riverside to Portsmouth?

    Yes. Cheapflights offers flight deals from Riverside to Portsmouth by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Riverside to Portsmouth?

    Currently, November is the cheapest month in which you can book a flight from Riverside to Portsmouth (average of $661). Flying from Riverside to Portsmouth in June is currently the most expensive (average of $1,097). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Riverside to Portsmouth

See prices for flight routes from nearby airports that may be better suited for you.
Los Angeles to Heathrow flights
San Francisco to Heathrow flights
Los Angeles to London City flights
San Francisco to Gatwick flights
San Francisco to London City flights
Los Angeles to Gatwick flights
Ontario to Heathrow flights
Los Angeles to Luton flights
Los Angeles to Stansted flights
San Diego to Heathrow flights
San Francisco to Stansted flights
San Francisco to Luton flights
Las Vegas to Heathrow flights
Oakland to Heathrow flights
Los Angeles to Edinburgh flights
San Diego to Gatwick flights
San Jose to Heathrow flights
Sacramento to Heathrow flights
San Diego to London City flights
San Francisco to Edinburgh flights
Burbank to Heathrow flights
Sacramento to Gatwick flights
Palm Springs to Heathrow flights
San Francisco to Southampton flights
San Jose to Gatwick flights
Santa Ana to Heathrow flights
Las Vegas to London City flights
Oakland to Gatwick flights
San Diego to Edinburgh flights
Las Vegas to Gatwick flights
Reno to Heathrow flights
Los Angeles to Southend flights
Sacramento to London City flights
Los Angeles to Manchester flights
San Francisco to Manchester flights
Ontario to Edinburgh flights
Long Beach to Heathrow flights
Las Vegas to Edinburgh flights
Los Angeles to Southampton flights
San Diego to Stansted flights
Santa Ana to Gatwick flights
Las Vegas to Luton flights
Ontario to Gatwick flights
Reno to Gatwick flights
Santa Ana to Edinburgh flights
Fresno to Heathrow flights
San Jose to Manchester flights
Sacramento to Edinburgh flights
Ontario to Manchester flights
Santa Rosa to Heathrow flights

Top 10 airlines flying from Riverside to Portsmouth

Discover the top 10 airlines that operate flights from Riverside to Portsmouth. 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 July 31, 2025.
AirlineCheapestAverageFlexibilityOn-time
WestJetCheapest$272Average$1,046FlexibilityNo cancel feeOn-time60%
JetBlueCheapest$273Average$791FlexibilityNo cancel feeOn-time62%
SWISSCheapest$336Average$900FlexibilityNo cancel feeOn-time79%
Norse Atlantic UKCheapest$362Average$686FlexibilityNo cancel feeOn-timeN/A
TAP AIR PORTUGALCheapest$375Average$673FlexibilityNo cancel feeOn-timeN/A
Scandinavian AirlinesCheapest$418Average$592FlexibilityNo cancel feeOn-time77%
LufthansaCheapest$427Average$732FlexibilityNo cancel feeOn-time76%
Aer LingusCheapest$476Average$994FlexibilityNo cancel feeOn-timeN/A
FinnairCheapest$540Average$720FlexibilityNo cancel feeOn-time76%
British AirwaysCheapest$553Average$822FlexibilityNo cancel feeOn-time70%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.