Best Time to Fly ATL to PWM: On-Time Stats by Hour & Airline
Hartsfield-Jackson Atlanta International → Portland International Jetport
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 75.4% of Atlanta (ATL) to Portland (PWM) flights arrived on time (642 scheduled flights). That is 2.2 points below the national average of 77.6%.
Delta Air Lines was the only reporting airline with regular flights on this route.
Over 24 months, Monday was the most reliable day (78% on time) and July the worst month (53%).
The cancellation rate was 1.1% (US average 1.8%).
ATL to PWM 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 | 75.4% | 57 min | 1.1% | 642 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly ATL to PWM
On-time arrival % by scheduled departure hour (local time), 1,233 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 8am–9am | Limited data | 1 | |
| 9am–10am | 83.7% | 0.4% | 248 |
| 10am–11am | 85.0% | 0.0% | 133 |
| 11am–12pm | Limited data | 2 | |
| 1pm–2pm | Limited data | 4 | |
| 2pm–3pm | Limited data | 5 | |
| 3pm–4pm | 55.5% | 3.5% | 114 |
| 7pm–8pm | 76.2% | 0.5% | 203 |
| 8pm–9pm | 68.4% | 0.9% | 211 |
| 9pm–10pm | 71.4% | 1.3% | 312 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on ATL to PWM
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) | Limited data | 21 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 63.3% | -16.9 pts | 0.0% | 30 |
| Summer peak (Jun 15 - Aug 15) | 60.0% | -20.2 pts | 2.6% | 350 |
| All other days | 80.2% | — | 0.4% | 832 |
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).