Best Time to Fly IAD to STL
Washington to St. Louis — month-by-month delay data from the Bureau of Transportation Statistics.
Best month
June
1% on time
Worst month
June
1% on time
IAD → STL on-time performance by month
23
JanFebMarAprMayJunJulAugSepOctNovDec
Worse
Better
Monthly breakdown
| Month | On-time | Cancel rate | Flights |
|---|---|---|---|
| June | 1% | 0% | 29 |
| July | 1% | 0% | 31 |
| August | 1% | 0% | 31 |
| September | 1% | 0% | 30 |
| October | 1% | 0% | 30 |
| November | 1% | 0% | 30 |
| December | 1% | 0% | 20 |
Frequently asked
What is the best month to fly from IAD to STL?
June has the highest on-time rate at 1% for flights from Washington to St. Louis.
What is the worst month to fly IAD to STL?
June has the lowest on-time rate at 1%, often due to summer thunderstorms.
How often are IAD to STL flights delayed?
On average, 1% of flights from IAD to STL arrive on time. That means about 99% experience some form of delay.
Source: Bureau of Transportation Statistics.