Route Reliability

Route reliability

Seattle (SEA) to Atlanta (ATL): which airline is most on time?

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

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

Seattle, WAAtlanta, GA

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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

SEA to ATL

Seattle, WA to Atlanta, GA

On time
83.0%vs 75.6% U.S. average Better than average
Cancelled
0.7%vs 1.9% U.S. average Better than average
60+ min late
4.6%vs 8.1% U.S. average Better than average
Scheduled flights
3,294in 12 months2 airlines
Most reliable airline
Delta Air Lines83.2% on time · 2,402 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 SEA to ATL, 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 83.2% 0.7% 5.0% 84 min 0.5% 2,402
2. Alaska Airlines 82.3% 0.6% 3.6% 49 min 0.6% 892

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 Seattle (SEA) to Atlanta (ATL): 83.2% of its 2,402 scheduled flights arrived within 15 minutes of schedule, compared with 82.3% for Alaska Airlines. The gap is small, so treat the airlines as roughly equal on punctuality.
  • 0.7% of flights on this route were cancelled (about 1 in 143), 1.2 points lower than the U.S. average of 1.9%.
  • 4.6% of flights, about 1 in 22, arrived an hour or more late. When a flight was late (15+ minutes), the average arrival delay was 74 min.
  • Overall, 83.0% of flights on this route arrived on time, 7.4 points higher than the U.S. average of 75.6%.
  • Over the last 3 years, November was the most reliable month on this route (87.6% on time) and July the least reliable (68.8%).
  • Cancellations peaked in January, when 3.8% of flights were cancelled.
  • Flights scheduled to depart 6 am to 7 am were the most punctual (94.5% on time); flights scheduled to depart 9 am to 10 am were the least (74.2%).
  • In the other direction, Atlanta (ATL) to Seattle (SEA), 76.0% of flights were on time and 0.7% were cancelled. Compare airlines ATL to SEA.

Best and worst months to fly SEA to ATL

Jan 79.7%
Feb 87.2%
Mar 82.9%
Apr 81.7%
May 80.5%
Jun 77.7%
Jul 68.8%
Aug 78.9%
Sep 84.9%
Oct 85.8%
Nov 87.6%
Dec 82.3%
Share of scheduled flights on time 12-month average 83.0%
All airlines combined, by calendar month, September 2023 to August 2026 (3 years pooled). Scale starts at zero.
Show as table
PeriodOn timeFlights
January 79.7% 661
February 87.2% 586
March 82.9% 706
April 81.7% 763
May 80.5% 902
June 77.7% 1,002
July 68.8% 1,072
August 78.9% 1,023
September 84.9% 935
October 85.8% 908
November 87.6% 806
December 82.3% 812
Best and worst calendar month by airline, September 2023 to August 2026.
AirlineBest monthWorst month
Delta Air Lines November (90.2%) July (72.2%)
Alaska Airlines February (90.2%) July (60.0%)

Month by month, last 12 months

Sep 90.1%
Oct 83.7%
Nov 85.9%
Dec 78.1%
Jan 85.4%
Feb 90.6%
Mar 78.4%
Apr 84.9%
May 82.6%
Jun 83.4%
Jul 74.4%
Aug 82.6%
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 90.1% 284
Oct 2025 83.7% 295
Nov 2025 85.9% 256
Dec 2025 78.1% 269
Jan 2026 85.4% 213
Feb 2026 90.6% 191
Mar 2026 78.4% 231
Apr 2026 84.9% 251
May 2026 82.6% 298
Jun 2026 83.4% 325
Jul 2026 74.4% 348
Aug 2026 82.6% 333

Best and worst departure times

6a 94.5%
7a 80.9%
8a 80.1%
9a 74.2%
10a 86.3%
11a 76.4%
12p Insufficient sample
1p 81.5%
2p Insufficient sample
3p 79.8%
4p 83.5%
5p Insufficient sample
9p 84.5%
10p 87.4%
11p 87.0%
Share of scheduled flights on time
By scheduled local departure hour at SEA, 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 94.5% 364
Departing 7 am to 8 am 80.9% 324
Departing 8 am to 9 am 80.1% 171
Departing 9 am to 10 am 74.2% 291
Departing 10 am to 11 am 86.3% 51
Departing 11 am to noon 76.4% 348
Departing noon to 1 pm Insufficient sample 17
Departing 1 pm to 2 pm 81.5% 211
Departing 2 pm to 3 pm Insufficient sample 42
Departing 3 pm to 4 pm 79.8% 218
Departing 4 pm to 5 pm 83.5% 351
Departing 5 pm to 6 pm Insufficient sample 31
Departing 9 pm to 10 pm 84.5% 233
Departing 10 pm to 11 pm 87.4% 151
Departing 11 pm to midnight 87.0% 491
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 Seattle, WA (SEA) to Atlanta, GA (ATL), 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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