Best Time to Fly SEA to ATL: On-Time Stats by Hour & Airline
Seattle/Tacoma International → Hartsfield-Jackson Atlanta International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 83.5% of Seattle (SEA) to Atlanta (ATL) flights arrived on time (3,277 scheduled flights). That is 5.9 points above the national average of 77.6%.
Among 2 airlines, Delta Air Lines led with 84.0% on time and Alaska Airlines was last with 82.4%.
Over 24 months, Tuesday was the most reliable day (85% on time) and July the worst month (73%).
The cancellation rate was 0.6% (US average 1.8%).
SEA to ATL on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| Delta Air Lines | 84.0% | 83 min | 0.6% | 2,380 |
| Alaska Airlines | 82.4% | 47 min | 0.6% | 897 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly SEA to ATL
On-time arrival % by scheduled departure hour (local time), 6,647 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 91.4% | 0.4% | 770 |
| 7am–8am | 82.8% | 0.3% | 641 |
| 8am–9am | 84.4% | 1.5% | 393 |
| 9am–10am | 74.2% | 0.2% | 393 |
| 10am–11am | 67.2% | 0.0% | 174 |
| 11am–12pm | 76.3% | 0.2% | 644 |
| 12pm–1pm | 83.1% | 0.7% | 138 |
| 1pm–2pm | 83.3% | 0.2% | 423 |
| 2pm–3pm | 78.0% | 2.4% | 42 |
| 3pm–4pm | 84.8% | 0.4% | 557 |
| 4pm–5pm | 76.8% | 0.7% | 587 |
| 5pm–6pm | 83.3% | 0.0% | 156 |
| 9pm–10pm | 82.5% | 0.5% | 426 |
| 10pm–11pm | 80.5% | 0.8% | 368 |
| 11pm–12am | 79.8% | 0.9% | 935 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on SEA to ATL
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 85.6% | +2.0 pts | 0.0% | 118 |
| Christmas & New Year (Dec 20 - Jan 3) | 80.2% | -3.4 pts | 0.8% | 264 |
| Summer peak (Jun 15 - Aug 15) | 73.9% | -9.7 pts | 0.6% | 1,396 |
| All other days | 83.6% | — | 0.5% | 4,869 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).