Boston to Miami Flight Delays
Sample size: 11,056 BOS–MIA flights, January 2023 to December 2025 (BTS). 22.45% of Boston to Miami flights arrived at least 15 minutes late. That is 1.7 points better than the 24.2% median for those routes, making this one of the steadier pairings in the network. Departure time moves the odds more than anything else on this route: 05:00 departures run 7.65% late against 42.78% for 16:00. Tuesday is the calmest day at 17.09%, Sunday the worst at 25.63%. Cancellations (2024 to 2025) peak in July at 3.3% of scheduled flights and bottom out in September at 0.2%. 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.
BOS airport delay guide · MIA airport delay guide · Predict a BOS to MIA flight
Best time to fly BOS to MIA
The best time to fly BOS to MIA is the 5 AM departure and fly on a Tuesday, not a Sunday (17.09% against 25.63%): 7.65% of 5 AM flights arrived 15+ minutes late, against 42.78% at 4 PM.
Lowest observed delay rates depart 05:00–07:00. The highest sit at 15:00–16:00, 19:00. 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 |
|---|---|---|
| 05:00 | 7.65% | 1,072 |
| 06:00 | 10.89% | 854 |
| 07:00 | 13.9% | 2,194 |
| 08:00 | 15.99% | 888 |
| 09:00 | 18.31% | 415 |
| 10:00 | 27.3% | 597 |
| 11:00 | 26.67% | 315 |
| 12:00 | 20.67% | 566 |
| 13:00 | 24.78% | 581 |
| 14:00 | 28.41% | 271 |
| 15:00 | 37.92% | 1,076 |
| 16:00 | 42.78% | 720 |
| 17:00 | 28.86% | 738 |
| 18:00 | 32.09% | 564 |
| 19:00 | 38.32% | 107 |
BOS to MIA flight time and distance
Scheduled gate-to-gate time from BOS to MIA is a median 3 h 37 min. Flights actually took a median 3 h 27 min gate to gate, including 2 h 57 min in the air. 4.8% ran 30 or more minutes over schedule and 70.5% arrived sooner than scheduled (BTS data, January 2023 to December 2025).
BOS to MIA is 1,258 miles (BTS data).
| Airline | Scheduled (median) | Actual (median) | In the air (median) | 30+ min over schedule | Flights |
|---|---|---|---|---|---|
| American Airlines | 3 h 38 min | 3 h 27 min | 2 h 56 min | 3.8% | 6,544 |
| Delta Air Lines | 3 h 37 min | 3 h 29 min | 2 h 56 min | 6.5% | 2,092 |
| JetBlue Airways | 3 h 33 min | 3 h 26 min | 2 h 58 min | 6.6% | 1,336 |
| Spirit Airlines (ceased operating May 2026) | 3 h 38 min | 3 h 25 min | 2 h 58 min | 5.3% | 861 |
How late, and why
When a BOS to MIA flight was late (15+ minutes), it arrived an average of 72 minutes late (median 43). 8.3% of all completed flights arrived an hour or more late (BTS data, 2023 to 2025).
Of the delay minutes on late BOS to MIA flights, 34.3% were caused by the air-traffic system (volume, non-extreme weather, airport operations), 34.2% by the airline (crew, maintenance, ground handling), 29.7% by a late incoming aircraft, 1.6% by extreme weather and 0.2% by security (BTS data, 2023 to 2025).
| Cause | Share of delay minutes |
|---|---|
| air-traffic system | 34.3% |
| airline | 34.2% |
| late incoming aircraft | 29.7% |
| extreme weather | 1.6% |
| 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.
BOS to MIA delays by day of week
| Day | Delayed 15+ min | Flights observed |
|---|---|---|
| Mon | 23.01% | 1,586 |
| Tue | 17.09% | 1,551 |
| Wed | 20.83% | 1,517 |
| Thu | 23.33% | 1,603 |
| Fri | 23.92% | 1,597 |
| Sat | 23.04% | 1,567 |
| Sun | 25.63% | 1,635 |
Month-by-month cancellation pattern
Share of scheduled BOS–MIA 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 | 0.86% | 701 |
| Feb | 0.87% | 686 |
| Mar | 1.66% | 722 |
| Apr | 0.65% | 770 |
| May | 0.62% | 640 |
| Jun | 2.65% | 567 |
| Jul | 3.3% | 575 |
| Aug | 1.38% | 581 |
| Sep | 0.2% | 493 |
| Oct | 1.11% | 539 |
| Nov | 1.05% | 573 |
| Dec | 2.11% | 665 |
Airlines on BOS to MIA: 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% | 17.96% | 1.37% | 4,513 |
| Delta Air Lines | 20% | 27.01% | 1.36% | 1,471 |
| JetBlue Airways | 13% | 30.69% | 1.5% | 935 |
| Spirit Airlines (ceased operations 2 May 2026) | 6% | 30.55% | 1.09% | 459 |
Related pages
- BOS delays: rate, worst hours and live risk
- MIA 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 BOS to MIA flight
Check your odds: Will my flight be delayed? · Will my flight be cancelled?
BOS vs MIA: airport conditions
Both ends of a route shape its delay profile. These are DelayGuard's operational scores for Boston and Miami.
| Measure | BOS (Boston) | MIA (Miami) |
|---|---|---|
| Congestion | high | high |
| Weather risk | moderate | moderate |
| NAS vulnerability | high | high |
| Average taxi-out | 16 min | 17 min |
| Runways | 6 | 4 |
BOS to MIA questions
- How long is the flight from Boston to Miami?
- Scheduled gate-to-gate time from BOS to MIA is a median 3 h 37 min, and flights actually took a median 3 h 27 min including 2 h 57 min in the air. 4.8% ran 30+ minutes over schedule (BTS data, January 2023 to December 2025).
- How often do BOS to MIA flights get delayed?
- Across 11,056 recorded BOS–MIA departures, January 2023 to December 2025 (BTS), 22.45% arrived at least 15 minutes late. Departure time matters most: 5:00 departures run 7.65% late against 42.78% for 16:00. Actual delay frequency varies by airline, time of day, and season.
- What is the best time of year to fly BOS to MIA?
- Boston (MA) sees its highest delays during December–February (winter weather) and June–August (summer storms). Miami (FL) peaks during June–September (convective/thunderstorm season). The dominant seasonal risk on this route sits at the origin (Boston) — use the DelayGuard predictor to check conditions for your specific travel date.
- Which airline is most reliable on BOS to MIA?
- On BOS→MIA, American Airlines has the lowest measured delay rate at 17.96% of 6,544 flights, and JetBlue Airways the highest at 30.69% (BTS, January 2023 to December 2025). Delta Air Lines cancels the fewest at 1.36% (2024 to 2025). These are route-specific figures, not airline-wide averages.
- How late are BOS to MIA flights when they are delayed?
- When a BOS to MIA flight was late (15+ minutes), it arrived an average of 72 minutes late (median 43). 8.3% 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.