69% of flights from Boston to Chicago arrived on time over the past 12 months. That is worse than the typical U.S. route. The 6 a.m. departures ran on time 91% of the time; the 7 p.m. ones 44%. Most reliable airline: United Airlines (73%). 16% of flights arrived more than an hour late or not at all.
How late?
The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for BOS → ORD: when a flight was late, it was under 45 minutes late 44% of the time. About 1 in 8 flights landed an hour or more late, and 1 in 33 three hours or more; 3.0% were cancelled outright.
- On time or early69%
- 15–30 min late7.6%
- 30–60 min late7.3%
- 1–2 hours late6.5%
- 2–3 hours late2.7%
- 3+ hours late3.0%
- Diverted0.5%
- Cancelled3.0%
Share of all 7,860 scheduled flights, past 12 months, by arrival time against schedule.
By airline
| Airline | Flights | On time | Cancelled | Typical arrival | 1h+ late | Avg when late | Operated by |
|---|---|---|---|---|---|---|---|
| American Airlines | 3,198 | 71% | 3.4% | −9 min | 12.9% | +97 min | American Airlines 68%, Republic Airways 19%, Envoy 14% |
| United Airlines | 2,791 | 73% | 1.8% | −3 min | 10.0% | +86 min | United Airlines |
| Delta Air Lines | 1,319 | 61% | 4.4% | +1 min | 14.3% | +75 min | Delta Air Lines 74%, Republic Airways 26% |
| JetBlue | 552 | 64% | 3.3% | −2 min | 14.5% | +80 min | JetBlue |
Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.
Best time of day to fly
On-time rate by scheduled departure hour (local time at BOS). Delays build through the day as late planes knock on, so early flights usually do best.
By airline and hour
| Departs | American Airlines | United Airlines | Delta Air Lines | JetBlue |
|---|---|---|---|---|
| 5 a.m. | 89% | — | — | — |
| 6 a.m. | 91% | 92% | — | — |
| 7 a.m. | 82% | 81% | 75% | 79% |
| 8 a.m. | 90% | 90% | — | 71% |
| 9 a.m. | — | 84% | — | — |
| 10 a.m. | 78% | 80% | — | — |
| 11 a.m. | 70% | 84% | 70% | — |
| noon | 77% | 82% | 68% | — |
| 1 p.m. | 73% | — | — | — |
| 2 p.m. | 73% | — | — | — |
| 3 p.m. | 60% | 60% | — | — |
| 4 p.m. | 64% | 52% | 56% | — |
| 5 p.m. | 51% | 52% | — | 38% |
| 6 p.m. | 61% | 48% | — | — |
| 7 p.m. | 45% | — | 41% | — |
| 8 p.m. | — | 51% | 45% | — |
Last flight of the day
On BOS → ORD, each airline's last flight of the day was cancelled 4.4% of the time, against 2.7% for its earlier flights (1.6× as often). It arrived 3+ hours late 4.6% of the time (earlier flights: 2.8%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.
| Airline | Last departure | Last: cancelled | Last: 3h+ late | Earlier: cancelled | Next morning |
|---|---|---|---|---|---|
| American Airlines | 7:17 p.m. | 4.9% | 4.7% | 3.2% | first flight 5:10 a.m. |
| JetBlue | 5:20 p.m. | 5.3% | 4.8% | 1.6% | first flight 8:10 a.m. |
| Delta Air Lines | 8:45 p.m. | 5.0% | 3.0% | 4.2% | first flight 7:30 a.m. |
| United Airlines | 8:20 p.m. | 2.7% | 6.0% | 1.7% | first flight 6:00 a.m. |
Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.
If you need to be in ORD tonight, book an earlier flight so there's a backup if it's cancelled.
By month
Each calendar month pooled over 2023–2026. Best: December (80%). Worst: August (67%).
By day of week
| Day | Flights | On time | Cancelled |
|---|---|---|---|
| Monday | 1,214 | 65% | 6.1% |
| Tuesday | 1,091 | 73% | 3.4% |
| Wednesday | 1,084 | 74% | 1.8% |
| Thursday | 1,162 | 71% | 1.9% |
| Friday | 1,181 | 69% | 2.5% |
| Saturday | 946 | 72% | 1.5% |
| Sunday | 1,182 | 63% | 3.2% |
Why flights were late
Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.
Cancellations: weather 148 · air traffic/airport 56 · airline 30
Month by month
Flight numbers on this route
Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.
| Flight | Departs | Flights | On time | Cancelled | Typical arrival | Operated by |
|---|---|---|---|---|---|---|
| AA 3324 | 5:00 a.m. | 138 | 92% | 1.5% | −19 min | American Airlines |
| UA 1414 | 6:00 a.m. | 337 | 92% | 1.8% | −7 min | United Airlines |
| AA 1509 | 7:00 a.m. | 206 | 89% | 0.0% | −18 min | American Airlines |
| B6 311 | 7:00 a.m. | 285 | 77% | 2.1% | −7 min | JetBlue |
| DL 2570 | 7:30 a.m. | 266 | 78% | 3.0% | −7 min | Delta Air Lines |
| AA 1239 | 8:35 a.m. | 165 | 90% | 1.2% | −18 min | American Airlines |
| UA 1349 | 9:50 a.m. | 308 | 84% | 1.6% | −11 min | United Airlines |
| UA 503 | 10:35 a.m. | 164 | 81% | 0.0% | −10 min | United Airlines |
| UA 1732 | 12:30 p.m. | 332 | 83% | 1.2% | −9 min | United Airlines |
| AA 3711 | 1:56 p.m. | 216 | 75% | 2.8% | −12 min | Envoy |
| B6 811 | 3:35 p.m. | 264 | 50% | 4.5% | +11 min | JetBlue |
| DL 2646 | 4:15 p.m. | 259 | 56% | 5.4% | +3 min | Delta Air Lines |
| UA 2040 | 4:25 p.m. | 360 | 52% | 2.2% | +11 min | United Airlines |
| UA 1015 | 6:23 p.m. | 305 | 48% | 4.3% | +14 min | United Airlines |
| UA 2229 | 8:20 p.m. | 150 | 50% | 2.7% | +9 min | United Airlines |
| DL 2804 | 8:45 p.m. | 140 | 41% | 5.0% | +20 min | Delta Air Lines |
Worst days in the past year
| Date | Flights | On time | Cancelled |
|---|---|---|---|
| Nov 30, 2025 | 25 | 0% | 2 |
| Feb 23, 2026 | 19 | 0% | 19 |
| Nov 29, 2025 | 19 | 0% | 7 |
| Jan 26, 2026 | 18 | 0% | 13 |
| Jan 25, 2026 | 18 | 6% | 10 |
Nearby airport alternatives
Other ways to make the same trip, using airports within 60 miles of Boston or Chicago. MHT → MDW has been 14 points more reliable.
| Route | Flights | On time | Cancelled |
|---|---|---|---|
| BOS → ORD (this route) | 7,860 | 69% | 3.0% |
| MHT → MDW Manchester-Boston to Chicago Midway | 529 | 83% | 0.8% |
| PVD → MDW Rhode Island T. F. Green to Chicago Midway | 778 | 81% | 1.4% |
| MHT → ORD Manchester-Boston to Chicago O'Hare | 614 | 81% | 2.1% |
| PVD → ORD Rhode Island T. F. Green to Chicago O'Hare | 1,727 | 71% | 4.0% |
| BOS → MDW Boston Logan to Chicago Midway | 1,368 | 68% | 2.0% |
Questions
How often are flights from BOS to ORD on time?
69% of 7,860 scheduled flights from Boston, MA to Chicago, IL arrived within 15 minutes of schedule between September 2025 and August 2026. 3.0% were cancelled.
What is the best time of day to fly BOS to ORD?
Flights scheduled to leave at 6 a.m. were the most reliable (91% on time). The 7 p.m. departures were the least (44%).
Which airline is most on time from BOS to ORD?
United Airlines: 73% of its 2,791 flights on the route arrived on time. American Airlines: 71%. Delta Air Lines: 61%. JetBlue: 64%.
What month has the most delays from BOS to ORD?
August (67% on time). The best month is December (80%), over 2023–2026.
Is the last flight of the day from BOS to ORD more likely to be cancelled?
Yes. Each airline's last BOS–ORD flight of the day was cancelled 4.4% of the time over the past year, against 2.7% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.
Related
- ORD → BOS (return)
- Boston Logan (BOS) delays by hour
- Flights into Chicago O'Hare (ORD)
- American Airlines on-time record
- United Airlines on-time record
- Delta Air Lines on-time record
- JetBlue on-time record
- Connecting off this flight? Check the risk
Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.