Best Time to Fly ATL to IAD: On-Time Stats by Hour & Airline
Hartsfield-Jackson Atlanta International → Washington Dulles International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 76.9% of Atlanta (ATL) to Washington (IAD) flights arrived on time (3,992 scheduled flights). That is 0.7 points below the national average of 77.6%.
Among 3 airlines, United Airlines led with 82.1% on time and Frontier Airlines was last with 63.4%.
Over 24 months, Wednesday was the most reliable day (81% on time) and July the worst month (64%).
The cancellation rate was 2.0% (US average 1.8%).
ATL to IAD 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 |
|---|---|---|---|---|
| United Airlines | 82.1% | 77 min | 0.9% | 1,094 |
| Delta Air Lines | 78.2% | 77 min | 2.7% | 2,224 |
| Frontier Airlines | 63.4% | 82 min | 1.7% | 653 |
| Republic Airways | Limited data | 21 | ||
80%+ good 70–79.9% fair <70% poor
Best time of day to fly ATL to IAD
On-time arrival % by scheduled departure hour (local time), 7,729 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 95.6% | 1.8% | 327 |
| 6am–7am | Limited data | 20 | |
| 7am–8am | 85.1% | 1.9% | 527 |
| 8am–9am | 88.1% | 1.5% | 205 |
| 9am–10am | 86.4% | 1.3% | 988 |
| 10am–11am | 79.6% | 2.0% | 355 |
| 11am–12pm | 84.1% | 1.4% | 147 |
| 12pm–1pm | 80.6% | 0.4% | 506 |
| 1pm–2pm | 73.0% | 3.4% | 146 |
| 2pm–3pm | 73.9% | 1.2% | 1,256 |
| 3pm–4pm | 66.2% | 0.7% | 278 |
| 4pm–5pm | 68.9% | 2.9% | 410 |
| 5pm–6pm | 69.9% | 2.0% | 149 |
| 6pm–7pm | 76.9% | 3.3% | 180 |
| 7pm–8pm | 75.0% | 0.9% | 1,124 |
| 8pm–9pm | 62.5% | 4.5% | 67 |
| 9pm–10pm | 61.1% | 3.0% | 270 |
| 10pm–11pm | 66.4% | 3.5% | 743 |
| 11pm–12am | 90.3% | 0.0% | 31 |
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 IAD
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) | 76.2% | -3.1 pts | 0.0% | 151 |
| Christmas & New Year (Dec 20 - Jan 3) | 71.8% | -7.5 pts | 1.1% | 283 |
| Summer peak (Jun 15 - Aug 15) | 67.9% | -11.4 pts | 3.2% | 1,425 |
| All other days | 79.3% | — | 1.4% | 5,870 |
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).