Route Reliability

Route reliability

Atlanta (ATL) to St. Louis (STL): which airline is most on time?

On-time arrivals, cancellations and long delays for every airline that reported nonstop flights from Atlanta, GA (ATL) to St. Louis, MO (STL), September 2025 to August 2026.

Historical performance Official DOT data through August 2026 · Not live flight status

Atlanta, GASt. Louis, MO

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Three-letter airport codes, nonstop U.S. domestic flights. One direction at a time.

Route at a glance · September 2025 to August 2026

ATL to STL

Atlanta, GA to St. Louis, MO

On time
80.5%vs 75.6% U.S. average Better than average
Cancelled
1.4%vs 1.9% U.S. average Better than average
60+ min late
5.4%vs 8.1% U.S. average Better than average
Scheduled flights
3,678in 12 months3 airlines
Most reliable airline
Delta Air Lines82.9% on time · 2,348 flights

On time more often than the U.S. average, with fewer cancellations.

Compared with all U.S. flights, September 2025 to August 2026. “About average” means within 1.5 points for on time, 0.3 for cancelled and 1 for 60+ minutes late.

Airlines on this route

Ranked by on-time arrival

Airlines from ATL to STL, September 2025 to August 2026. Rates are shares of all scheduled flights.
Airline On time Cancelled 60+ min late Avg delay when late Diverted Flights
1. Delta Air Lines Most reliable 82.9% 1.9% 4.6% 56 min 0.1% 2,348
2. Southwest Airlines 78.6% 0.4% 6.4% 57 min 0.1% 1,095
3. Frontier Airlines Small sample (under 300 flights) 65.1% 1.7% 9.4% 52 min 0.0% 235

On time = arrived within 15 minutes of schedule. Avg delay when late = average arrival delay of flights 15+ minutes late. "Most reliable" needs at least 300 flights in 12 months. Tap a heading to sort.

What this means

Delta Air Lines has the strongest record on this route.

  • Delta Air Lines had the best on-time record from Atlanta (ATL) to St. Louis (STL): 82.9% of its 2,348 scheduled flights arrived within 15 minutes of schedule, compared with 78.6% for Southwest Airlines.
  • 1.4% of flights on this route were cancelled (about 1 in 71), 0.5 points lower than the U.S. average of 1.9%.
  • 5.4% of flights, about 1 in 19, arrived an hour or more late. When a flight was late (15+ minutes), the average arrival delay was 56 min.
  • Overall, 80.5% of flights on this route arrived on time, 4.9 points higher than the U.S. average of 75.6%.
  • Over the last 3 years, September was the most reliable month on this route (89.5% on time) and July the least reliable (71.0%).
  • Cancellations peaked in January, when 4.1% of flights were cancelled.
  • Flights scheduled to depart 6 am to 7 am were the most punctual (93.1% on time); flights scheduled to depart 8 pm to 9 pm were the least (62.2%).
  • In the other direction, St. Louis (STL) to Atlanta (ATL), 82.9% of flights were on time and 1.6% were cancelled. Compare airlines STL to ATL.

Best and worst months to fly ATL to STL

Jan 75.7%
Feb 85.8%
Mar 80.2%
Apr 80.7%
May 76.5%
Jun 78.9%
Jul 71.0%
Aug 81.1%
Sep 89.5%
Oct 87.7%
Nov 86.1%
Dec 81.0%
Share of scheduled flights on time 12-month average 80.5%
All airlines combined, by calendar month, September 2023 to August 2026 (3 years pooled). Scale starts at zero.
Show as table
PeriodOn timeFlights
January 75.7% 798
February 85.8% 741
March 80.2% 843
April 80.7% 867
May 76.5% 931
June 78.9% 942
July 71.0% 979
August 81.1% 954
September 89.5% 894
October 87.7% 949
November 86.1% 878
December 81.0% 924
Best and worst calendar month by airline, September 2023 to August 2026.
AirlineBest monthWorst month
Delta Air Lines September (90.7%) July (71.4%)
Southwest Airlines February (88.6%) July (70.3%)

Month by month, last 12 months

Sep 92.1%
Oct 85.6%
Nov 78.2%
Dec 78.1%
Jan 79.6%
Feb 80.7%
Mar 74.6%
Apr 81.6%
May 80.3%
Jun 81.1%
Jul 73.3%
Aug 79.6%
Share of scheduled flights on time U.S. average 75.6%
All airlines combined, September 2025 to August 2026. Scale starts at zero.
Show as table
PeriodOn timeFlights
Sep 2025 92.1% 317
Oct 2025 85.6% 348
Nov 2025 78.2% 285
Dec 2025 78.1% 311
Jan 2026 79.6% 279
Feb 2026 80.7% 254
Mar 2026 74.6% 283
Apr 2026 81.6% 299
May 2026 80.3% 330
Jun 2026 81.1% 318
Jul 2026 73.3% 330
Aug 2026 79.6% 324

Best and worst departure times

6a 93.1%
7a 90.2%
8a 86.3%
9a 87.1%
10a 81.6%
11a 88.1%
12p 75.5%
1p 84.9%
2p 80.8%
3p 83.5%
4p 59.6%
5p 74.1%
6p 83.0%
7p 66.3%
8p 62.2%
9p 78.6%
10p 82.9%
11p 78.9%
Share of scheduled flights on time
By scheduled local departure hour at ATL, September 2025 to August 2026. Hours with no scheduled flights are omitted. Scale starts at zero.
Show as table
PeriodOn timeFlights
Departing 6 am to 7 am 93.1% 116
Departing 7 am to 8 am 90.2% 295
Departing 8 am to 9 am 86.3% 401
Departing 9 am to 10 am 87.1% 249
Departing 10 am to 11 am 81.6% 103
Departing 11 am to noon 88.1% 252
Departing noon to 1 pm 75.5% 106
Departing 1 pm to 2 pm 84.9% 212
Departing 2 pm to 3 pm 80.8% 297
Departing 3 pm to 4 pm 83.5% 254
Departing 4 pm to 5 pm 59.6% 89
Departing 5 pm to 6 pm 74.1% 317
Departing 6 pm to 7 pm 83.0% 100
Departing 7 pm to 8 pm 66.3% 175
Departing 8 pm to 9 pm 62.2% 283
Departing 9 pm to 10 pm 78.6% 126
Departing 10 pm to 11 pm 82.9% 123
Departing 11 pm to midnight 78.9% 180
Woman at an airport window watching a plane take off
Photo: Depositphotos (licensed stock, illustrative only). Credits

Sources & data dates

Source
U.S. DOT Bureau of Transportation Statistics, Reporting Carrier On-Time Performance (1987-present)
Period
September 2025 to August 2026 (12 months); month-of-year patterns September 2023 to August 2026
Data through
August 2026
Processed
2026-11-03
Scope
Nonstop scheduled flights from Atlanta, GA (ATL) to St. Louis, MO (STL), one direction. Airlines that report to the DOT only.
Method
Rates use all scheduled flights as the denominator; cancelled and diverted flights count as not on time. Figures based on fewer than 50 scheduled flights are suppressed. Full methodology.

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