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 47% on the cost of your flight, compared to a flight in the afternoon.
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.