Cheap flights from Dulles Intl (IAD) to St. Augustine (UST)
Find cheap flights from Dulles Intl to St. Augustine 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.Find flight deals from Dulles Intl to St. Augustine
Discover tips and strategies to find the most affordable flight options for your journey from Dulles Intl (IAD) to St. Augustine (UST). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated December 3, 2025.
Most accurate provider | eDreams 3 stars |
|---|---|
Most trusted provider | eDreams 3 stars |
Compare providers for flights from Dulles Intl to St. Augustine
Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Dulles Intl to St. Augustine in December.
| Provider | Price Accuracy | Trust Score* |
|---|---|---|
| Price Accuracy2 stars | Trust Score*3 stars | |
| Price Accuracy3 stars | Trust Score*1 star | |
| Price Accuracy3 stars | Trust Score*3 stars |
- Most accurate provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-St. Augustine flights, users find the pricing of eDreams to be most consistent on Cheapflights vs. eDreams Users can find the same prices on Washington, D.C. Dulles Intl Airport-St. Augustine flight deals on Cheapflights vs. eDreams >95% of the time. Price accuracy is based on data collected from Washington, D.C. Dulles Intl Airport-St. Augustine flight searches over the past month and is updated monthly.
- Most trusted provider: When it comes to deals on Washington, D.C. Dulles Intl Airport-St. Augustine flights, Cheapflights users trust eDreams the most. eDreams has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Washington, D.C. Dulles Intl Airport-St. Augustine flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.
Best time to book a flight from Dulles Intl to St. Augustine
Have a flexible travel schedule? Discover the best time to fly to St. Augustine from Dulles Intl with our price prediction graph.
Cheapflights Insights
Everything you need to know about your flight from Washington, D.C. Dulles Intl Airport to St. Augustine
What is the cheapest month to book a flight from Washington, D.C. Dulles Intl Airport to St. Augustine?
Currently, March is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to St. Augustine (average of $47). Flying from Washington, D.C. Dulles Intl Airport to St. Augustine in August is currently the most expensive (average of $81). 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 IAD to UST?
It’s optimal to fly from Washington, D.C. Dulles Intl Airport to St. Augustine in the evening. By choosing this option you can save up to 46% on the cost of your flight, compared to a flight in the afternoon.
What is the cheapest day to fly from Washington, D.C. Dulles Intl Airport to St. Augustine?
Travelers seeking maximum savings on their Washington, D.C. Dulles Intl Airport to St. Augustine flight should consider departing on Sunday evenings when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
How often are flights from Washington, D.C. to St. Augustine delayed?
About 14% of weekly flights between Washington, D.C. and St. Augustine have experienced delays in the past year, with the average delay time being 157 minutes.
What is the most punctual flight time for Washington, D.C. to St. Augustine flights?
Historically, flights departing in the morning are less likely to be delayed, whereas flights leaving in the evening tend to experience delays more often.
What day of the week experiences the fewest flight delays on this route?
Monday tends to have the lowest number of delays on this route, whereas Wednesday has historically faced a higher average of delays compared to other days of the week.
Which airline has the best punctuality record on Washington, D.C. to St. Augustine flights?
Over the last year, Frontier have had the lowest number of delays on this route, with just 10% of flights being delayed.