Flight OddsUA3991 GRR → IAH
United Airlines · Grand Rapids, MI to Houston, TX · 32 flights observed, 2026-03-29 to 2026-04-29 · 1,042 mi
UA3991 covers more than one route in the data window — the stats below are for GRR → IAH, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
78%
Median delay
-2 min
90th percentile
+34 min
Cancellation rate
0%
How often is UA3991 on time?
Across 32 flights on GRR → IAH from 2026-03-29 to 2026-04-29, UA3991 arrived within 15 minutes of schedule 78% of the time. The median arrival delay was -2 min, and the worst 10% of flights arrived +34 min or later. 0% of flights were cancelled.
Delay distribution
Arrival delay for completed flights (excludes cancellations and diversions).
| Arrival | Flights | Share |
|---|---|---|
| Early / on-time | 25 | 78% |
| 16-30 min | 2 | 6% |
| 31-60 min | 2 | 6% |
| 61-120 min | 1 | 3% |
| 2+ hrs | 2 | 6% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2026-03 | 3 | 100% | -20 min |
| 2026-04 | 29 | 76% | +17 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 5 | 100% |
| Tue | 5 | 100% |
| Wed | 5 | 80% |
| Thu | 4 | 50% |
| Fri | 4 | 75% |
| Sat | 4 | 75% |
| Sun | 5 | 60% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…