Route profile
SJU→IAH
Flight reliability, delays and best times to fly from San Juan to Houston, 2,007 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 82% of comparable major US routes (4,598 compared)
Calculated from 2,877 flights. How this is calculated
SJU → IAH arrives on time 84.3% of the time; the return trip, IAH → SJU, arrives on time 80.1% of the time, a 4.2-point gap between the two directions of the same city pair.
SJU → IAH spends 26.4 minutes on the ground on a 2,007-mile trip: 16.2 minutes from pushback to wheels-up at SJU and 10.3 minutes from touchdown to gate at IAH.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
This route holds up about the same all year, a steadier seasonal pattern than 95% of 3,357 comparable routes.
89.6% on time in its best month (June) against 79.8% in its worst (March).
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 3,357 in the comparison.
When it goes wrong
July 2023 – July 2026
28 min late
against a median of 10 min early
Percentiles over 2,877 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at IAH after arriving from SJU.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 31% | Likely to miss |
| 45 min | 15% | High risk |
| 60 min | 9.5% | Some risk |
| 90 min | 4.9% | Low risk |
| 120 min | 3.0% | Low 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 1.08% of the time and diverts 0.52% of the time, which a late arrival never shows up in.
Chance of missing is the share of 2,831 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 28 minutes late (90th-percentile gate arrival delay), over 2,877 operations.
Any other layover length: connection checker.
Best time to fly
SJU → IAH flights departing 5–9 AM arrived on time 93.9% of the time, against 75.1% for 12–3 PM departures, a gap of 18.8 percentage points.
By departure window
By departure hour
- 12 AM to 1 AM: too few flights to score
- 2 AM: 96.3% on time from 160 flights
- 3 AM to 6 AM: too few flights to score
- 7 AM: 94.3% on time from 906 flights
- 8 AM to 9 AM: too few flights to score
- 10 AM: 91.5% on time from 120 flights
- 11 AM to 1 PM: too few flights to score
- 2 PM: 74.8% on time from 710 flights
- 3 PM: 76.1% on time from 507 flights
- 4 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why SJU → IAH runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding and fueling, all within the carrier’s control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for SJU → IAH. Only delays of 15 minutes or more are attributed.
Late-arriving aircraft is the largest cause on SJU → IAH, at 49.9%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 93.9% of the time and 12–3 PM departures 75.1%.
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 |
|---|---|---|---|---|---|
| United Airlines | 2,543 | 85.6% | 0.87% | -10 min | 4.4% |
| Spirit Airlines | 334 | 74.0% | 2.69% | -4 min | 9.0% |
United Airlines flew 88.4% of the 2,877 flights listed. Spirit Airlines cancelled 2.69% of its flights here against 0.87% for United Airlines.
United Airlines arrived on time 11.6 percentage points more often than Spirit Airlines on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Saturday the least, a gap of 5.0 percentage points.
By month
- Jan: 81.3%
- Feb: 87.7%
- Mar: 79.8%
- Apr: 84.4%
- May: 80.3%
- Jun: 89.6%
- Jul: 85.5%
- Aug: 83.1%
- Sep: 84.3%
- Oct: 85.8%
- Nov: 84.2%
- Dec: 84.8%
March is historically the weakest month and June the strongest, a spread of 9.8 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 87.6% against 84.3% in the 12 months before — improving by 3.3 percentage points.
Data and methodology
Calculated by FlyerIntel from 2,877 SJU → IAH 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