San Juan (SJU) to Houston (IAH): On-Time Performance
Data through July 2026
The calendar drives reliability on SJU–IAH. September 2025 flights landed on schedule 94% of the time, but September 2024 dropped to 73% — a gap of 22 points. Across the full period the route averages 85% on-time against a national 78%.
- On-time
- 85%
- arrived <15 min late
- Avg delay
- 10 min
- completed flights
- Cancelled
- 1.1%
- Flights/day
- 2.5
- last 12 months
- Duration
- 4h 59m
- scheduled
- Distance
- 2,007 mi
Best airline from SJU to IAH
2 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| United Airlinesmost reliable | 87% | 9 min | 0.9% | 1,772 |
| Spirit Airlines | 74% | 16 min | 2.0% | 303 |
Monthly on-time trend
Best time to fly from SJU to IAH
Aim for departures around 2 a.m. (96% on-time); avoid 4 p.m. departures (71%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 87% | 8 min |
| Tuesdaybest | 88% | 9 min |
| Wednesday | 88% | 8 min |
| Thursday | 85% | 9 min |
| Friday | 85% | 11 min |
| Saturday | 81% | 14 min |
| Sunday | 85% | 11 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft54%
- Airline operations20%
- National airspace system26%
Frequently asked questions
- How often are flights from SJU to IAH delayed?
- 15% of SJU–IAH 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 10 minutes.
- Which airline is most reliable from SJU to IAH?
- United Airlines has the best on-time record on this route at 87%, based on 1,772 flights. 2 airlines flew SJU–IAH frequently enough to compare in this period.
- What is the best time of day to fly from SJU to IAH?
- Departures around 2 a.m. have the best record (96% on-time), while departures around 4 p.m. have the worst (71%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from SJU to IAH?
- The scheduled SJU–IAH flight time averages 4h 59m over 2,007 miles. Actual arrival times vary — flights on this route land 15+ minutes late 15% of the time.
- How often are SJU to IAH flights cancelled?
- 1.1% 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 SJU to IAH?
- September 2024 was the roughest month in this dataset, with only 73% of arrivals on time. The best was September 2025 at 94%. If your dates are flexible, that 22-point gap is worth planning around.
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Based on 2,075 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.