Route profile
BOS→MIA
Flight reliability, delays and best times to fly from Boston to Miami, 1,258 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 40% of comparable major US routes (4,598 compared)
Calculated from 11,477 flights. How this is calculated
BOS → MIA arrives on time 78.2% of the time; the return trip, MIA → BOS, arrives on time 70.3% of the time, an 8.0-point gap between the two directions of the same city pair.
BOS → MIA spends 32.2 minutes on the ground on a 1,258-mile trip: 21.5 minutes from pushback to wheels-up at BOS and 10.7 minutes from touchdown to gate at MIA.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
This route has stayed remarkably steady year over year, a smaller swing than 100% of 5,368 comparable routes.
78.4% on time over the most recent 12 months (2025-08 to 2026-07), against 78.4% in the 12 months before (2024-08 to 2025-07), virtually unchanged.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 5,368 in the comparison.
Why BOS → MIA flights are cancelled
July 2023 – July 2026
BOS → MIA cancelled 182 of 11,477 scheduled flights — about 1 in every 63. The reason filed most often was extreme weather, 72.5% of the cancellations coded on this route — about 1 in every 87 scheduled flights.
Share of cancellations
Of 182 cancelled departures carrying a reason code.
What each reason means
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
132 cancellations, 72.5% of the total.
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
39 cancellations, 21.4% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
11 cancellations, 6.0% of the total.
A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.
0 cancellations, 0.0% of the total.
Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
182 coded cancellations were recorded on BOS → MIA; the section appears from 50.
When it goes wrong
July 2023 – July 2026
48 min late
against a median of 9 min early
Percentiles over 11,477 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at MIA after arriving from BOS.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 35% | Likely to miss |
| 45 min | 21% | High risk |
| 60 min | 14% | Some risk |
| 90 min | 8.2% | Some risk |
| 120 min | 5.0% | Some risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 1.59% of the time and diverts 0.37% of the time, which a late arrival never shows up in.
Chance of missing is the share of 11,253 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 48 minutes late (90th-percentile gate arrival delay), over 11,477 operations.
Any other layover length: connection checker.
Best time to fly
BOS → MIA flights departing 5–9 AM arrived on time 88.4% of the time, against 64.0% for 3–6 PM departures, a gap of 24.4 percentage points.
By departure window
By departure hour
- 12 AM to 4 AM: too few flights to score
- 5 AM: 93.3% on time from 1,127 flights
- 6 AM: 90.2% on time from 965 flights
- 7 AM: 86.6% on time from 2,207 flights
- 8 AM: 85.1% on time from 923 flights
- 9 AM: 81.4% on time from 331 flights
- 10 AM: 76.4% on time from 658 flights
- 11 AM: 72.8% on time from 294 flights
- 12 PM: 78.0% on time from 653 flights
- 1 PM: 75.5% on time from 560 flights
- 2 PM: 69.8% on time from 299 flights
- 3 PM: 63.2% on time from 1,161 flights
- 4 PM: 57.0% on time from 575 flights
- 5 PM: 71.3% on time from 665 flights
- 6 PM: 67.4% on time from 748 flights
- 7 PM: 63.9% on time from 186 flights
- 8 PM: 54.7% on time from 121 flights
- 9 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why BOS → MIA runs late
July 2023 – July 2026
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
the inbound aircraft was late, so this flight started late
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for BOS → MIA. Only delays of 15 minutes or more are attributed.
How this route holds up in bad weather
July 2023 – July 2026
Bad weather raises cancellations by a similar amount at both ends of BOS to MIA: 3.9 times the normal rate at BOS and 3.3 times at MIA. Cancelled in bad weather against normal hours: BOS 5.3% against 1.4%, MIA 4.5% against 1.3%. Flights that did leave MIA in bad weather arrived on time 50.6% of the time, against 74.1% in normal hours.
Bad weather and normal hours at the airports
Scheduled departures, July 2023 – July 2026| Departures from | BOS | MIA |
|---|---|---|
| Cancelled in bad weather | 5.3% | 4.5% |
| Cancelled in normal hours | 1.4% | 1.3% |
| Arrived on time, bad weather | 65.1% | 50.6% |
| Arrived on time, normal hours | 79.7% | 74.1% |
| Departures in bad weather | 60,840 | 15,746 |
Of the carriers on this route, Delta Air Lines (3.1% cancelled against 5.8% for the other carriers at BOS) cancelled the fewest departures from BOS in bad weather and Spirit Airlines (7.8% cancelled against 4.4% for the other carriers at BOS) the most.
This route’s airlines in bad weather at BOS
All departures from BOS| Airline | Bad-weather departures | Cancelled | Other carriers |
|---|---|---|---|
| Delta Air Lines | 10,971 | 3.1%below the others | 5.8% |
| American Airlines | 6,964 | 4.7%below the others | 5.5% |
| JetBlue | 17,332 | 5.4%about level | 5.1% |
| Spirit Airlines | 2,112 | 7.8%above the others | 4.4% |
These are airport figures, not route figures: every scheduled departure from BOS and MIA, to any destination, in hours the weather report called bad. The airline rows count each carrier’s departures from BOS on every route.
Weather source and limits. In full: BOS (airlines), MIA, What Weather Costs Each Airport, Who Cancels More When the Weather Turns, Airports That Change Places When Weather Turns.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| American Airlines | 6,971 | 82.8% | 1.48% | -12 min | 5.9% |
| Delta Air Lines | 2,369 | 73.4% | 1.60% | -6 min | 10.6% |
| JetBlue | 1,143 | 69.1% | 2.01% | -3 min | 13.0% |
| Spirit Airlines | 820 | 68.3% | 2.07% | -4 min | 14.6% |
American Airlines flew 61.7% of the 11,303 flights listed.
American Airlines arrived on time 14.5 percentage points more often than Spirit Airlines on this route.
Other ways to fly Boston to Miami
Airport pairs in the same two city markets, as the DOT defines them.
| Route | Flights | On time | Cancelled | Median delay | Score |
|---|---|---|---|---|---|
| BOS→MIA this route Boston to Miami | 11,477 | 78.2% | 1.59% | -9 min | 62 |
| BOS→FLL Boston to Fort Lauderdale | 10,020 | 68.7% | 2.22% | -2 min | 40 |
BOS → MIA is the most reliable pairing for this journey at 78.2% on time, against 68.7% for BOS → FLL.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
AA1418 (5:15 AM) arrived on time 93.3% of the time, 28.8 points more often than DL776 (3:20 PM) at 64.5%.
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Sunday the least, a gap of 8.0 percentage points.
By month
- Jan: 73.7%
- Feb: 76.6%
- Mar: 77.0%
- Apr: 82.6%
- May: 78.9%
- Jun: 78.6%
- Jul: 74.2%
- Aug: 75.6%
- Sep: 79.9%
- Oct: 85.0%
- Nov: 85.9%
- Dec: 72.9%
December is historically the weakest month and November the strongest, a spread of 13.0 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 68.4% from 294 flights
- August 2023: 71.8% from 329 flights
- September 2023: 72.6% from 275 flights
- October 2023: 86.7% from 302 flights
- November 2023: 85.8% from 326 flights
- December 2023: 76.7% from 353 flights
- January 2024: 71.9% from 353 flights
- February 2024: 80.8% from 345 flights
- March 2024: 75.3% from 343 flights
- April 2024: 86.9% from 356 flights
- May 2024: 80.7% from 298 flights
- June 2024: 76.7% from 266 flights
- July 2024: 74.2% from 274 flights
- August 2024: 71.6% from 294 flights
- September 2024: 87.7% from 269 flights
- October 2024: 91.2% from 289 flights
- November 2024: 91.1% from 314 flights
- December 2024: 71.4% from 387 flights
- January 2025: 73.6% from 348 flights
- February 2025: 72.9% from 341 flights
- March 2025: 77.5% from 379 flights
- April 2025: 84.4% from 414 flights
- May 2025: 76.5% from 342 flights
- June 2025: 73.0% from 301 flights
- July 2025: 73.0% from 301 flights
- August 2025: 83.6% from 287 flights
- September 2025: 79.4% from 224 flights
- October 2025: 75.9% from 250 flights
- November 2025: 79.4% from 259 flights
- December 2025: 69.9% from 278 flights
- January 2026: 75.9% from 305 flights
- February 2026: 75.9% from 310 flights
- March 2026: 78.2% from 325 flights
- April 2026: 76.0% from 334 flights
- May 2026: 79.9% from 280 flights
- June 2026: 86.7% from 264 flights
- July 2026: 81.9% from 268 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 78.4% against 78.4% in the 12 months before — broadly unchanged.
Data and methodology
Calculated by FlyerIntel from 11,477 BOS → MIA flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed