Route on-time record
STL to DCA: most on-time flights and the best time to fly
St Louis (St. Louis Lambert International Airport) to Washington (Ronald Reagan Washington National Airport). 2,410 nonstop flights in Jun 2025 to May 2026, 73% arrived within 15 minutes and 2.6% were cancelled. The most reliable flight number was Southwest 4450 at 8:35 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
STL → DCA
St Louis to Washington: 2,410 nonstop flights a year
On time (12 months)
73%
Cancelled
2.6%
avg delay 22 min
Best time to leave
Before 9 AM
87% on time vs 58% 6 to 9 PM
Most reliable airline
Republic
72% chance on time
Lowest nonstop fare seen in the next two months: $118 (Southwest 3500 on 2026-11-11). Fares open on our travel partner (Aviasales). Pick the flight number you chose here.
Most reliable nonstop flights
Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.
#1 · Southwest 4450
8:35 AM → 11:35 AM2h 00m nonstop
Local times, typical schedule. Last flown 2026-05-31.
89%
chance on time
- On time (history)
- 93%
- Cancelled
- 0.0%
- Avg arrival delay
- 2 min
- Arrived on time 93% of the time (55 flights, Jun 2025 to May 2026).
- Never cancelled in 55 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 87% on time; 6 to 9 PM: 58%).
- Short track record (55 flights), so its score leans on the airline's record at this hour.
Limited track record · 55 flights
Find Southwest 4450 fares Opens this date on Aviasales#2 · Southwest 1283
8:20 AM → 11:15 AM1h 55m nonstop
Local times, typical schedule. Last flown 2026-04-06.
88%
chance on time
- On time (history)
- 93%
- Cancelled
- 0.0%
- Avg arrival delay
- 5 min
- Arrived on time 93% of the time (27 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 87% on time; 6 to 9 PM: 58%).
- Short track record (27 flights), so its score leans on the airline's record at this hour.
Limited track record · 27 flights
Find Southwest 1283 fares Opens this date on Aviasales#3 · Southwest 359
12:05 PM → 3:05 PM2h 00m nonstop
Local times, typical schedule. Last flown 2026-05-30.
81%
chance on time
- On time (history)
- 100%
- Cancelled
- 0.0%
- Avg arrival delay
- 0 min
- Arrived on time 100% of the time (8 flights, Jun 2025 to May 2026).
- Lands inside DCA's trouble window: 63% of its 194 ground stops and delay programs started between 1 PM and 7 PM.
- Short track record (8 flights), so its score leans on the airline's record at this hour.
Limited track record · 8 flights
Find Southwest 359 fares Opens this date on Aviasales#4 · PSA 5454 · sold as American Eagle
9:56 AM → 1:08 PM2h 12m nonstop
Local times, typical schedule. Last flown 2026-05-20.
79%
chance on time
- On time (history)
- 89%
- Cancelled
- 0.0%
- Avg arrival delay
- 22 min
- Arrived on time 89% of the time (38 flights, Jun 2025 to May 2026).
- Never cancelled in 38 scheduled flights.
- Lands inside DCA's trouble window: 63% of its 194 ground stops and delay programs started between 1 PM and 7 PM.
- 92% of its delay minutes came from the plane arriving late from an earlier flight.
Limited track record · 38 flights
Find 9:56 AM flight fares Opens this date on Aviasales#5 · PSA 5411 · sold as American Eagle
6:00 AM → 9:15 AM2h 15m nonstop
Local times, typical schedule. Last flown 2026-05-20. Same departure also flew as PSA 5288; its record covers all of them.
76%
chance on time
- On time (history)
- 80%
- Cancelled
- 4.2%
- Avg arrival delay
- 26 min
- Arrived on time 80% of the time (91 flights, Jun 2025 to May 2026).
- Cancelled 4.2% of the time (4 of 95).
- Leaves in this route's most on-time window (Before 9 AM: 87% on time; 6 to 9 PM: 58%).
Moderate track record · 91 flights
Find 6:00 AM flight fares Opens this date on Aviasales#6 · Southwest 1714
3:25 PM → 6:25 PM2h 00m nonstop
Local times, typical schedule. Last flown 2026-05-30.
72%
chance on time
- On time (history)
- 100%
- Cancelled
- 0.0%
- Avg arrival delay
- 1 min
- Arrived on time 100% of the time (8 flights, Jun 2025 to May 2026).
- Lands inside DCA's trouble window: 63% of its 194 ground stops and delay programs started between 1 PM and 7 PM.
- Short track record (8 flights), so its score leans on the airline's record at this hour.
Limited track record · 8 flights
Find Southwest 1714 fares Opens this date on Aviasales#7 · PSA 5652 · sold as American Eagle
9:36 AM → 12:44 PM2h 08m nonstop
Local times, typical schedule. Last flown 2026-04-05.
70%
chance on time
- On time (history)
- 64%
- Cancelled
- 4.2%
- Avg arrival delay
- 90 min
- Arrived on time 64% of the time (22 flights, Jun 2025 to May 2026).
- Short track record (22 flights), so its score leans on the airline's record at this hour.
Limited track record · 22 flights
Find 9:36 AM flight fares Opens this date on Aviasales#8 · PSA 5015 · sold as American Eagle
5:08 AM → 8:28 AM2h 20m nonstop
Local times, typical schedule. Last flown 2026-05-31.
70%
chance on time
- On time (history)
- 70%
- Cancelled
- 9.1%
- Avg arrival delay
- 75 min
- Arrived on time 70% of the time (10 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 87% on time; 6 to 9 PM: 58%).
- Short track record (10 flights), so its score leans on the airline's record at this hour.
Limited track record · 10 flights
Find 5:08 AM flight fares Opens this date on Aviasales#9 · Southwest 4451
1:20 PM → 4:20 PM2h 00m nonstop
Local times, typical schedule. Last flown 2026-05-31.
69%
chance on time
- On time (history)
- 72%
- Cancelled
- 0.0%
- Avg arrival delay
- 14 min
- Arrived on time 72% of the time (47 flights, Jun 2025 to May 2026).
- Never cancelled in 47 scheduled flights.
- Lands inside DCA's trouble window: 63% of its 194 ground stops and delay programs started between 1 PM and 7 PM.
- Short track record (47 flights), so its score leans on the airline's record at this hour.
Limited track record · 47 flights
Find Southwest 4451 fares Opens this date on Aviasales#10 · Southwest 548
1:30 PM → 4:30 PM2h 00m nonstop
Local times, typical schedule. Last flown 2026-04-06.
67%
chance on time
- On time (history)
- 65%
- Cancelled
- 3.6%
- Avg arrival delay
- 41 min
- Arrived on time 65% of the time (26 flights, Jun 2025 to May 2026).
- Lands inside DCA's trouble window: 63% of its 194 ground stops and delay programs started between 1 PM and 7 PM.
- Short track record (26 flights), so its score leans on the airline's record at this hour.
Limited track record · 26 flights
Find Southwest 548 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Republic Airways (sold as American Eagle, Delta Connection or United Express)72%
199 flights · 77% on time as flown · 3.1% cancel
- Southwest Airlines72%
1,399 flights · 73% on time as flown · 1.5% cancel
- PSA Airlines (sold as American Eagle)71%
581 flights · 75% on time as flown · 4.9% cancel
- American Airlines66%
209 flights · 66% on time as flown · 2.5% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM87%
718 flights · avg delay 15 min
- 9 AM to noon78%
266 flights · avg delay 27 min
- Noon to 3 PM72%
437 flights · avg delay 21 min
- 3 to 6 PM64%
572 flights · avg delay 26 min
- 6 to 9 PM58%
417 flights · avg delay 27 min
Best day: Saturday (83%). Worst: Sunday (72%).
Smarter routing
Nearby airports that run more on time
STL → BWI 80% chance on time
St. Louis Lambert International Airport to Baltimore/Washington International Thurgood Marshall Airport · 1,288 flights a year · 30 mi from your airports · yours: 71%
On time by month
All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.
What delays this route
- Late-arriving aircraft41%
- Airline (crew, maintenance, boarding)33%
- Air traffic control and airport volume23%
- Severe weather3%
Share of delay minutes by the cause airlines report to the US DOT.
Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure
STL to DCA questions
- What time of day is best to fly STL to DCA?
- Before 9 AM: 87% of flights arrived on time, against 58% for departures 6 to 9 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
- Which airline is most on time from STL to DCA?
- Republic, with a season-adjusted 72% chance of operating and arriving on time over 199 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
- What is the worst month for delays on STL to DCA?
- July (68% on time); the best was November (84%), averaged over Jun 2023 to May 2026.
- Is this a prediction for my flight?
- No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.
More routes from STL
- DCA to STL (return)
- STL to ATL 85%
- STL to DEN 75%
- STL to ORD 71%
- STL to LGA 75%
- STL to MCO 78%
- STL to DFW 74%
- STL to PHX 76%
- STL to LAS 79%
- STL to DAL 77%
- STL to DTW 83%
- STL to MSP 80%
- STL to CLT 83%
Live status: FAA delays and ground stops