Route on-time record
ATL to STL: most on-time flights and the best time to fly
Atlanta (Hartsfield Jackson Atlanta International Airport) to St Louis (St. Louis Lambert International Airport). 3,718 nonstop flights in Jun 2025 to May 2026, 82% arrived within 15 minutes and 1.6% were cancelled. The most reliable flight number was Southwest 3243 at 7:00 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
ATL → STL
Atlanta to St Louis: 3,718 nonstop flights a year
On time (12 months)
82%
Cancelled
1.6%
avg delay 11 min
Best time to leave
Before 9 AM
91% on time vs 71% 6 to 9 PM
Most reliable airline
Delta
82% chance on time
Lowest nonstop fare seen in the next two months: $90 (Southwest 4625 on 2026-11-05). 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 3243
7:00 AM → 7:45 AM1h 45m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 268, 2416, 3941; its record covers all of them.
91%
chance on time
- On time (history)
- 93%
- Cancelled
- 0.0%
- Avg arrival delay
- 3 min
- Arrived on time 93% of the time (80 flights, Jun 2025 to May 2026).
- Never cancelled in 80 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 6 to 9 PM: 71%).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
Moderate track record · 80 flights
Find Southwest 3243 fares Opens this date on Aviasales#2 · Delta 1571
8:23 AM → 9:05 AM1h 42m nonstop
Local times, typical schedule. Last flown 2026-05-31.
88%
chance on time
- On time (history)
- 91%
- Cancelled
- 3.1%
- Avg arrival delay
- 5 min
- Arrived on time 91% of the time (313 flights, Jun 2025 to May 2026).
- Cancelled 3.1% of the time (10 of 323).
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 6 to 9 PM: 71%).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
Strong track record · 313 flights
Find Delta 1571 fares Opens this date on Aviasales#3 · Southwest 2453
9:05 AM → 9:50 AM1h 45m nonstop
Local times, typical schedule. Last flown 2026-05-30.
86%
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).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
- Short track record (8 flights), so its score leans on the airline's record at this hour.
Limited track record · 8 flights
Find Southwest 2453 fares Opens this date on Aviasales#4 · Delta 1485
2:54 PM → 3:32 PM1h 40m nonstop
Local times, typical schedule. Last flown 2026-05-31.
84%
chance on time
- On time (history)
- 86%
- Cancelled
- 1.4%
- Avg arrival delay
- 8 min
- Arrived on time 86% of the time (289 flights, Jun 2025 to May 2026).
- Departs inside ATL's trouble window: 59% of its 96 ground stops and delay programs started between 1 PM and 7 PM.
Strong track record · 289 flights
Find Delta 1485 fares Opens this date on Aviasales#5 · Delta 543
2:36 PM → 3:13 PM1h 37m nonstop
Local times, typical schedule. Last flown 2026-04-12.
82%
chance on time
- On time (history)
- 83%
- Cancelled
- 2.8%
- Avg arrival delay
- 11 min
- Arrived on time 83% of the time (35 flights, Jun 2025 to May 2026).
- Departs inside ATL's trouble window: 59% of its 96 ground stops and delay programs started between 1 PM and 7 PM.
- Short track record (35 flights), so its score leans on the airline's record at this hour.
Limited track record · 35 flights
Find Delta 543 fares Opens this date on Aviasales#6 · Delta 1400
10:22 AM → 11:09 AM1h 44m nonstop
Local times, typical schedule. Last flown 2026-05-31.
82%
chance on time
- On time (history)
- 83%
- Cancelled
- 2.7%
- Avg arrival delay
- 12 min
- Arrived on time 83% of the time (142 flights, Jun 2025 to May 2026).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
Moderate track record · 142 flights
Find Delta 1400 fares Opens this date on Aviasales#7 · Southwest 899
1:45 PM → 2:30 PM1h 45m nonstop
Local times, typical schedule. Last flown 2026-04-06.
82%
chance on time
- On time (history)
- 74%
- Cancelled
- 0.0%
- Avg arrival delay
- 13 min
- Arrived on time 74% of the time (23 flights, Jun 2025 to May 2026).
- Departs inside ATL's trouble window: 59% of its 96 ground stops and delay programs started between 1 PM and 7 PM.
- 61% of its delay minutes came from the plane arriving late from an earlier flight.
- Short track record (23 flights), so its score leans on the airline's record at this hour.
Limited track record · 23 flights
Find Southwest 899 fares Opens this date on Aviasales#8 · Delta 1102
8:27 PM → 9:06 PM1h 40m nonstop
Local times, typical schedule. Last flown 2026-05-31.
79%
chance on time
- On time (history)
- 83%
- Cancelled
- 3.5%
- Avg arrival delay
- 11 min
- Arrived on time 83% of the time (137 flights, Jun 2025 to May 2026).
- Cancelled 3.5% of the time (5 of 142).
- Leaves in this route's least on-time window (6 to 9 PM: 71% on time; Before 9 AM: 91%).
- Departs outside ATL's trouble window (1 PM to 7 PM, when 59% of its 96 ground stops and delay programs started).
Moderate track record · 137 flights
Find Delta 1102 fares Opens this date on Aviasales#9 · Delta 1393
5:16 PM → 5:53 PM1h 40m nonstop
Local times, typical schedule. Last flown 2026-05-31.
77%
chance on time
- On time (history)
- 80%
- Cancelled
- 3.9%
- Avg arrival delay
- 13 min
- Arrived on time 80% of the time (249 flights, Jun 2025 to May 2026).
- Cancelled 3.9% of the time (10 of 259).
- Departs inside ATL's trouble window: 59% of its 96 ground stops and delay programs started between 1 PM and 7 PM.
Strong track record · 249 flights
Find Delta 1393 fares Opens this date on Aviasales#10 · Southwest 2288
2:10 PM → 2:55 PM1h 45m nonstop
Local times, typical schedule. Last flown 2026-05-31.
75%
chance on time
- On time (history)
- 70%
- Cancelled
- 0.0%
- Avg arrival delay
- 14 min
- Arrived on time 70% of the time (30 flights, Jun 2025 to May 2026).
- Never cancelled in 30 scheduled flights.
- Departs inside ATL's trouble window: 59% of its 96 ground stops and delay programs started between 1 PM and 7 PM.
- 60% of its delay minutes came from the plane arriving late from an earlier flight.
Limited track record · 30 flights
Find Southwest 2288 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Delta Air Lines82%
2,380 flights · 83% on time as flown · 2.0% cancel
- Southwest Airlines80%
1,153 flights · 80% on time as flown · 0.9% cancel
- Frontier Airlines71%
185 flights · 70% on time as flown · 1.6% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM91%
766 flights · avg delay 5 min
- 9 AM to noon88%
631 flights · avg delay 8 min
- Noon to 3 PM83%
598 flights · avg delay 10 min
- 3 to 6 PM78%
688 flights · avg delay 15 min
- 6 to 9 PM71%
646 flights · avg delay 19 min
- After 9 PM76%
389 flights · avg delay 15 min
Best day: Wednesday (86%). Worst: Sunday (73%).
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
- Airline (crew, maintenance, boarding)45%
- Late-arriving aircraft39%
- Air traffic control and airport volume11%
- Severe weather5%
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
ATL to STL questions
- What time of day is best to fly ATL to STL?
- Before 9 AM: 91% of flights arrived on time, against 71% 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 ATL to STL?
- Delta, with a season-adjusted 82% chance of operating and arriving on time over 2,380 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 ATL to STL?
- July (73% on time); the best was September (90%), 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 ATL
- STL to ATL (return)
- ATL to LGA 73%
- ATL to MCO 69%
- ATL to FLL 69%
- ATL to DCA 69%
- ATL to DFW 73%
- ATL to ORD 71%
- ATL to EWR 72%
- ATL to MIA 70%
- ATL to TPA 71%
- ATL to PHL 73%
- ATL to DEN 76%
- ATL to BWI 74%
Live status: FAA delays and ground stops