Boston (BOS) to Chicago (ORD): On-Time Performance
Data through May 2026
Boston (BOS) to Chicago (ORD) effectively runs on two schedules. In November 2024, 89% of arrivals were on time; in October 2025 that fell to 64% — a 25-point seasonal swing. Across the full period the route averages 75% on-time against a national 78%. Morning departures also hold up better than evening ones (87% vs 57%), which matters most in the rough months.
- On-time
- 75%
- arrived <15 min late
- Avg delay
- 20 min
- completed flights
- Cancelled
- 1.9%
- Flights/day
- 21
- last 12 months
- Duration
- 2h 59m
- scheduled
- Distance
- 867 mi
Best airline from BOS to ORD
7 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Spirit Airlinesmost reliable | 84% | 10 min | 6.5% | 153 |
| United Airlines | 78% | 18 min | 1.4% | 5,093 |
| Envoy Air | 77% | 19 min | 2.1% | 982 |
| American Airlines | 75% | 22 min | 1.9% | 3,717 |
| JetBlue Airways | 75% | 19 min | 1.1% | 1,178 |
| Republic Airways | 73% | 19 min | 3.9% | 1,600 |
| Delta Air Lines | 70% | 24 min | 1.8% | 1,907 |
Monthly on-time trend
Best time to fly from BOS to ORD
Aim for departures around 6 a.m. (92% on-time); avoid 7 p.m. departures (54%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 75% | 22 min |
| Tuesdaybest | 81% | 16 min |
| Wednesday | 78% | 16 min |
| Thursday | 74% | 21 min |
| Friday | 73% | 20 min |
| Saturday | 77% | 19 min |
| Sunday | 72% | 24 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft42%
- Airline operations23%
- National airspace system32%
- Weather3%
Frequently asked questions
- How often are flights from BOS to ORD delayed?
- 25% of BOS–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 20 minutes.
- Which airline is most reliable from BOS to ORD?
- Spirit Airlines has the best on-time record on this route at 84%, based on 153 flights. 7 airlines flew BOS–ORD frequently enough to compare in this period.
- What is the best time of day to fly from BOS to ORD?
- Departures around 6 a.m. have the best record (92% on-time), while departures around 7 p.m. have the worst (54%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from BOS to ORD?
- The scheduled BOS–ORD flight time averages 2h 59m over 867 miles. Actual arrival times vary — flights on this route land 15+ minutes late 25% of the time.
- How often are BOS to ORD flights cancelled?
- 1.9% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, slightly above the national rate of 1.6%.
- What is the worst month to fly from BOS to ORD?
- October 2025 was the roughest month in this dataset, with only 64% of arrivals on time. The best was November 2024 at 89%. If your dates are flexible, that 25-point gap is worth planning around.
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Based on 14,632 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.