Washington (IAD) to Chicago (ORD): On-Time Performance
Data through May 2026
Washington (IAD) to Chicago (ORD) effectively runs on two schedules. In September 2024, 92% of arrivals were on time; in July 2025 that fell to 64% — a 28-point seasonal swing. Across the full period the route averages 77% on-time against a national 78%. Morning departures also hold up better than evening ones (89% vs 66%), which matters most in the rough months.
- On-time
- 77%
- arrived <15 min late
- Avg delay
- 16 min
- completed flights
- Cancelled
- 0.7%
- Flights/day
- 5.5
- last 12 months
- Duration
- 2h 14m
- scheduled
- Distance
- 588 mi
Monthly on-time trend
Best time to fly from IAD to ORD
Aim for departures around 6 a.m. (94% on-time); avoid 6 p.m. departures (40%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 77% | 17 min |
| Tuesday | 79% | 15 min |
| Wednesday | 76% | 15 min |
| Thursday | 75% | 18 min |
| Friday | 75% | 16 min |
| Saturdaybest | 81% | 14 min |
| Sunday | 77% | 19 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft21%
- Airline operations25%
- National airspace system45%
- Weather10%
Frequently asked questions
- How often are flights from IAD to ORD delayed?
- 23% of IAD–ORD flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 16 minutes.
- What is the best time of day to fly from IAD to ORD?
- Departures around 6 a.m. have the best record (94% on-time), while departures around 6 p.m. have the worst (40%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from IAD to ORD?
- The scheduled IAD–ORD flight time averages 2h 14m over 588 miles. Actual arrival times vary — flights on this route land 15+ minutes late 23% of the time.
- How often are IAD to ORD flights cancelled?
- 0.7% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from IAD to ORD?
- July 2025 was the roughest month in this dataset, with only 64% of arrivals on time. The best was September 2024 at 92%. If your dates are flexible, that 28-point gap is worth planning around.
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Based on 3,821 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.