Best Time to Fly IAD to ATL: On-Time Stats by Hour & Airline
Washington Dulles International → Hartsfield-Jackson Atlanta International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 78.7% of Washington (IAD) to Atlanta (ATL) flights arrived on time (3,989 scheduled flights). That is 1.1 points above the national average of 77.6%.
Delta Air Lines was the most punctual of the 3 airlines on the route at 80.7%, while Frontier Airlines trailed at 68.8%.
October has been the best month (86% on time) and Sunday the weakest day of the week (74%).
2.1% of flights were cancelled, versus 1.8% nationally.
IAD 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 | 80.7% | 95 min | 2.8% | 2,224 |
| United Airlines | 80.5% | 77 min | 0.7% | 1,092 |
| Frontier Airlines | 68.8% | 80 min | 2.1% | 652 |
| Republic Airways | Limited data | 21 | ||
80%+ good 70–79.9% fair <70% poor
Best time of day to fly IAD to ATL
On-time arrival % by scheduled departure hour (local time), 7,732 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 60.0% | 2.1% | 47 |
| 6am–7am | 84.0% | 2.4% | 924 |
| 7am–8am | 78.5% | 2.3% | 687 |
| 8am–9am | 87.7% | 0.5% | 758 |
| 9am–10am | 84.2% | 0.0% | 127 |
| 10am–11am | 84.7% | 2.7% | 557 |
| 11am–12pm | 86.4% | 1.4% | 142 |
| 12pm–1pm | 82.8% | 1.3% | 1,341 |
| 1pm–2pm | 78.8% | 0.6% | 157 |
| 2pm–3pm | 61.5% | 7.1% | 42 |
| 3pm–4pm | 76.7% | 1.3% | 524 |
| 4pm–5pm | 67.2% | 1.0% | 200 |
| 5pm–6pm | 67.7% | 1.4% | 1,165 |
| 6pm–7pm | 70.1% | 1.0% | 196 |
| 7pm–8pm | 72.3% | 4.7% | 406 |
| 8pm–9pm | 53.2% | 8.1% | 86 |
| 9pm–10pm | Limited data | 12 | |
| 10pm–11pm | 77.8% | 1.4% | 361 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on IAD 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) | 80.3% | +0.1 pts | 0.0% | 152 |
| Christmas & New Year (Dec 20 - Jan 3) | 77.3% | -2.9 pts | 1.4% | 283 |
| Summer peak (Jun 15 - Aug 15) | 70.7% | -9.5 pts | 3.5% | 1,430 |
| All other days | 80.2% | — | 1.4% | 5,867 |
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).