Best Time to Fly IAH to SJU: On-Time Stats by Hour & Airline
George Bush Intercontinental/Houston → Luis Munoz Marin International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 82.8% of Houston (IAH) to San Juan (SJU) flights arrived on time (928 scheduled flights). That is 5.1 points above the national average of 77.6%.
Among 2 airlines, United Airlines led with 84.3% on time and Spirit Airlines was last with 57.4%.
Over 24 months, Tuesday was the most reliable day (88% on time) and August the worst month (72%).
The cancellation rate was 0.5% (US average 1.8%).
IAH to SJU on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| United Airlines | 84.3% | 43 min | 0.3% | 872 |
| Spirit Airlines | 57.4% | 77 min | 3.6% | 56 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly IAH to SJU
On-time arrival % by scheduled departure hour (local time), 1,970 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | Limited data | 8 | |
| 6am–7am | Limited data | 9 | |
| 7am–8am | 87.5% | 0.0% | 88 |
| 9am–10am | 79.0% | 1.7% | 58 |
| 10am–11am | 77.8% | 0.3% | 713 |
| 11am–12pm | Limited data | 10 | |
| 1pm–2pm | 71.8% | 0.0% | 39 |
| 2pm–3pm | Limited data | 16 | |
| 3pm–4pm | 86.9% | 0.4% | 698 |
| 4pm–5pm | 66.7% | 0.0% | 42 |
| 5pm–6pm | Limited data | 8 | |
| 6pm–7pm | Limited data | 5 | |
| 11pm–12am | 85.3% | 1.1% | 276 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on IAH to SJU
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 75.0% | -10.0 pts | 0.0% | 36 |
| Christmas & New Year (Dec 20 - Jan 3) | 79.0% | -6.0 pts | 5.4% | 111 |
| Summer peak (Jun 15 - Aug 15) | 74.6% | -10.4 pts | 0.5% | 411 |
| All other days | 85.0% | — | 0.2% | 1,412 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).