Miami (MIA) to San Juan (SJU): On-Time Performance
Data through July 2026
Miami (MIA) to San Juan (SJU) effectively runs on two schedules. In October 2024, 90% of arrivals were on time; in July 2025 that fell to 63% — a 28-point seasonal swing. Across the full period the route averages 76% on-time against a national 78%. Morning departures also hold up better than evening ones (87% vs 67%), which matters most in the rough months.
- On-time
- 76%
- arrived <15 min late
- Avg delay
- 19 min
- completed flights
- Cancelled
- 0.8%
- Flights/day
- 7.2
- last 12 months
- Duration
- 2h 39m
- scheduled
- Distance
- 1,045 mi
Best airline from MIA to SJU
3 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| American Airlinesmost reliable | 77% | 17 min | 0.4% | 4,196 |
| Frontier Airlines | 76% | 25 min | 1.9% | 952 |
| Spirit Airlines | 70% | 25 min | 2.1% | 524 |
Monthly on-time trend
Best time to fly from MIA to SJU
Aim for departures around 7 a.m. (93% on-time); avoid 12 a.m. departures (44%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 79% | 18 min |
| Tuesday | 81% | 16 min |
| Wednesdaybest | 83% | 12 min |
| Thursday | 74% | 18 min |
| Friday | 77% | 18 min |
| Saturday | 71% | 22 min |
| Sunday | 71% | 26 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft43%
- Airline operations37%
- National airspace system15%
- Weather4%
Frequently asked questions
- How often are flights from MIA to SJU delayed?
- 24% of MIA–SJU flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 19 minutes.
- Which airline is most reliable from MIA to SJU?
- American Airlines has the best on-time record on this route at 77%, based on 4,196 flights. 3 airlines flew MIA–SJU frequently enough to compare in this period.
- What is the best time of day to fly from MIA to SJU?
- Departures around 7 a.m. have the best record (93% on-time), while departures around 12 a.m. have the worst (44%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from MIA to SJU?
- The scheduled MIA–SJU flight time averages 2h 39m over 1,045 miles. Actual arrival times vary — flights on this route land 15+ minutes late 24% of the time.
- How often are MIA to SJU flights cancelled?
- 0.8% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from MIA to SJU?
- July 2025 was the roughest month in this dataset, with only 63% of arrivals on time. The best was October 2024 at 90%. If your dates are flexible, that 28-point gap is worth planning around.
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Based on 5,688 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.