No delays reported for UA 1644 (SJU → IAH) as of 6:47 PM ET. It arrived on time 96.7% of the time in June-August 2026. When it was late, the average delay was 35 minutes. None were cancelled. Right now there are no reported delays at SJU, IAH.
Looks on time
Next leg SJU → IAH, scheduled 7:00 AM local time. No delays at SJU right now, and it usually runs on time.
Cancellation risk: Medium 0% of its flights were cancelled in June-August 2026; rough weather at IAH.
Estimate from the schedule, live position and airport conditions, if this flight operates today. Check United for official times.
Before you fly
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Route and schedule
| Leg | Scheduled | On time |
|---|---|---|
| SJU → IAH San Juan, PR to Houston, TX | 7:00 AM → 10:53 AM | 97% |
Local times. Schedules change; check your booking.
How reliable is UA 1644?
| Arrived on time (within 15 min) | 96.7% |
| Average delay when late | 35 min |
| Cancelled | 0% |
| Diverted | 0% |
| Flights tracked | 92 |
Best and worst days to fly UA 1644
UA 1644 was most reliable on Mondays (100% on time) and least reliable on Tuesdays (85%).
| Monday | |
| Tuesday | |
| Wednesday | |
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Why it runs late
| Late-arriving plane | |
| Airline (crew, maintenance) | |
| Air traffic system | |
| Extreme weather |
Share of delay minutes by cause, as reported by United to the Department of Transportation.
Other flights SJU → IAH
All flights on this route, ranked
Live status at its airports
We show airport-wide airport status, not this flight's gate or live position. For that, check the United app.
United delays and what you're owed · Airline phone numbers
About this data
On-time history: U.S. Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, June-August 2026. Live conditions: live airport status. "On time" means arriving within 15 minutes of schedule.
Common questions
Is UA 1644 delayed today?
Right now there are no reported delays at SJU, IAH. Checked 6:47 PM ET. For this flight's gate and exact status, check the United app.
Is UA 1644 usually on time?
UA 1644 arrived within 15 minutes of schedule 96.7% of the time in June-August 2026, with an average delay of 35 minutes when late.
How often is UA 1644 cancelled?
0% of UA 1644 flights were cancelled in June-August 2026.