Miami to Boston Flight Delays
Sample size: 11,078 MIA–BOS flights, January 2023 to December 2025 (BTS). 29.55% of Miami to Boston flights arrived at least 15 minutes late. That is 5.4 points worse than the 24.2% median for those routes, so schedule padding matters here. Departure time moves the odds more than anything else on this route: 07:00 departures run 11.38% late against 40.96% for 20:00. Tuesday is the calmest day at 26.45%, Sunday the worst at 35.41%. Cancellations (2024 to 2025) peak in July at 3.65% of scheduled flights and bottom out in September at 0%. Last updated: 2026-10-01.
These figures are historical US domestic rates, not a forecast for one departure. Use the US domestic delay forecast before you book.
MIA airport delay guide · BOS airport delay guide · Predict a MIA to BOS flight
Best time to fly MIA to BOS
The best time to fly MIA to BOS is the 7 AM departure and fly on a Tuesday, not a Sunday (26.45% against 35.41%): 11.38% of 7 AM flights arrived 15+ minutes late, against 40.96% at 8 PM.
Lowest observed delay rates depart 06:00–08:00. The highest sit at 14:00, 17:00, 20:00. Only departure hours with at least 100 recorded flights are listed, so sparse hours are blank rather than estimated.
| Departure hour | Delayed 15+ min | Flights observed |
|---|---|---|
| 06:00 | 15.46% | 427 |
| 07:00 | 11.38% | 167 |
| 08:00 | 11.58% | 1,002 |
| 09:00 | 16% | 125 |
| 10:00 | 21.84% | 522 |
| 11:00 | 23.95% | 1,791 |
| 12:00 | 33.07% | 1,028 |
| 13:00 | 27.12% | 177 |
| 14:00 | 39.93% | 576 |
| 15:00 | 33.91% | 404 |
| 16:00 | 26.33% | 357 |
| 17:00 | 39.62% | 780 |
| 18:00 | 36.28% | 328 |
| 19:00 | 39.05% | 1,475 |
| 20:00 | 40.96% | 747 |
| 21:00 | 30.92% | 1,106 |
MIA to BOS flight time and distance
Scheduled gate-to-gate time from MIA to BOS is a median 3 h 22 min. Flights actually took a median 3 h 14 min gate to gate, including 2 h 45 min in the air. 3.0% ran 30 or more minutes over schedule and 72.7% arrived sooner than scheduled (BTS data, January 2023 to December 2025).
MIA to BOS is 1,258 miles (BTS data).
| Airline | Scheduled (median) | Actual (median) | In the air (median) | 30+ min over schedule | Flights |
|---|---|---|---|---|---|
| American Airlines | 3 h 20 min | 3 h 12 min | 2 h 45 min | 2.7% | 6,564 |
| Delta Air Lines | 3 h 26 min | 3 h 17 min | 2 h 45 min | 2.6% | 2,096 |
| JetBlue Airways | 3 h 22 min | 3 h 16 min | 2 h 46 min | 4.1% | 1,328 |
| Spirit Airlines (ceased operating May 2026) | 3 h 25 min | 3 h 14 min | 2 h 46 min | 3.9% | 863 |
How late, and why
When a MIA to BOS flight was late (15+ minutes), it arrived an average of 77 minutes late (median 47). 12.0% of all completed flights arrived an hour or more late (BTS data, 2023 to 2025).
Of the delay minutes on late MIA to BOS flights, 38.7% were caused by a late incoming aircraft, 34.8% by the airline (crew, maintenance, ground handling), 21.1% by the air-traffic system (volume, non-extreme weather, airport operations), 5.2% by extreme weather and 0.2% by security (BTS data, 2023 to 2025).
| Cause | Share of delay minutes |
|---|---|
| late incoming aircraft | 38.7% |
| airline | 34.8% |
| air-traffic system | 21.1% |
| extreme weather | 5.2% |
| security | 0.2% |
BTS assigns causes to delay minutes on flights that arrived 15+ minutes late. "Air-traffic system" includes non-extreme weather that slows traffic.
MIA to BOS delays by day of week
| Day | Delayed 15+ min | Flights observed |
|---|---|---|
| Mon | 28.4% | 1,588 |
| Tue | 26.45% | 1,573 |
| Wed | 26.5% | 1,521 |
| Thu | 31.67% | 1,604 |
| Fri | 30.15% | 1,592 |
| Sat | 27.92% | 1,576 |
| Sun | 35.41% | 1,624 |
Month-by-month cancellation pattern
Share of scheduled MIA–BOS flights cancelled in each month, from BTS 2024–2025 on-time reporting. These are cancellations, not delays. Delay figures on this page cover January 2023 to December 2025.
| Month | Cancelled | Flights scheduled |
|---|---|---|
| Jan | 1.28% | 701 |
| Feb | 1.02% | 686 |
| Mar | 2.21% | 724 |
| Apr | 0.65% | 769 |
| May | 0.78% | 642 |
| Jun | 2.47% | 567 |
| Jul | 3.65% | 576 |
| Aug | 1.89% | 581 |
| Sep | 0% | 493 |
| Oct | 1.12% | 537 |
| Nov | 1.05% | 570 |
| Dec | 1.95% | 665 |
Airlines on MIA to BOS: delays and cancellations
American Airlines, Delta Air Lines and JetBlue Airways fly this route today. Spirit Airlines also appear in the history below but has ceased operations. Only carriers with at least 200 scheduled flights on the pairing are listed. Delay rates cover January 2023 to December 2025; cancellation rates cover 2024 to 2025.
| Airline | Share of flights | Delayed 15+ min | Cancelled | Flights scheduled |
|---|---|---|---|---|
| American Airlines | 61% | 28.53% | 1.37% | 4,515 |
| Delta Air Lines | 20% | 32.97% | 1.5% | 1,469 |
| JetBlue Airways | 13% | 35.62% | 2.36% | 933 |
| Spirit Airlines (ceased operations 2 May 2026) | 6% | 22.02% | 1.53% | 459 |
Related pages
- MIA delays: rate, worst hours and live risk
- BOS delays: rate, worst hours and live risk
- Boston to DC flights (BOS to DCA)
- DC to Boston flights (DCA to BOS)
- US airline cancellation rates
- Thanksgiving and Christmas 2026 flight delay guide
- Predict a MIA to BOS flight
Check your odds: Will my flight be delayed? · Will my flight be cancelled?
MIA vs BOS: airport conditions
Both ends of a route shape its delay profile. These are DelayGuard's operational scores for Miami and Boston.
| Measure | MIA (Miami) | BOS (Boston) |
|---|---|---|
| Congestion | high | high |
| Weather risk | moderate | moderate |
| NAS vulnerability | high | high |
| Average taxi-out | 17 min | 16 min |
| Runways | 4 | 6 |
MIA to BOS questions
- How long is the flight from Miami to Boston?
- Scheduled gate-to-gate time from MIA to BOS is a median 3 h 22 min, and flights actually took a median 3 h 14 min including 2 h 45 min in the air. 3.0% ran 30+ minutes over schedule (BTS data, January 2023 to December 2025).
- How often do MIA to BOS flights get delayed?
- Across 11,078 recorded MIA–BOS departures, January 2023 to December 2025 (BTS), 29.55% arrived at least 15 minutes late. Departure time matters most: 7:00 departures run 11.38% late against 40.96% for 20:00. Actual delay frequency varies by airline, time of day, and season.
- What is the best time of year to fly MIA to BOS?
- Miami (FL) sees its highest delays during June–September (convective/thunderstorm season). Boston (MA) peaks during December–February (winter weather) and June–August (summer storms). The dominant seasonal risk on this route sits at the destination (Boston) — use the DelayGuard predictor to check conditions for your specific travel date.
- Which airline is most reliable on MIA to BOS?
- On MIA→BOS, American Airlines has the lowest measured delay rate at 28.53% of 6,564 flights, and JetBlue Airways the highest at 35.62% (BTS, January 2023 to December 2025). American Airlines cancels the fewest at 1.37% (2024 to 2025). These are route-specific figures, not airline-wide averages.
- How late are MIA to BOS flights when they are delayed?
- When a MIA to BOS flight was late (15+ minutes), it arrived an average of 77 minutes late (median 47). 12.0% of all completed flights arrived an hour or more late (BTS data, 2023 to 2025).
- How accurate is DelayGuard's delay prediction for this route?
- DelayGuard's delay risk score comes from an ML model trained on BTS data (3.95 million US domestic flights, 2023 to mid-2025), with live weather data (within 5 days of departure) and FAA NAS advisories (within 6 hours) — a likelihood of delay, not a guarantee.
Delay figures reflect arrivals 15 or more minutes late in BTS on-time reporting. Cancellation figures are separate and count flights that never operated. Hours, days and months with fewer than 100 recorded flights are omitted rather than estimated.