Flight OddsUA521 ATL → IAH
United Airlines · Atlanta, GA to Houston, TX · 88 flights observed, 2026-02-12 to 2026-06-27 · 689 mi
UA521 covers more than one route in the data window — the stats below are for ATL → IAH, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
83%
Median delay
-11 min
90th percentile
+39 min
Cancellation rate
0%
How often is UA521 on time?
Across 88 flights on ATL → IAH from 2026-02-12 to 2026-06-27, UA521 arrived within 15 minutes of schedule 83% of the time. The median arrival delay was -11 min, and the worst 10% of flights arrived +39 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 | 73 | 83% |
| 16-30 min | 4 | 5% |
| 31-60 min | 3 | 3% |
| 61-120 min | 4 | 5% |
| 2+ hrs | 4 | 5% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2026-02 | 17 | 94% | -13 min |
| 2026-03 | 28 | 86% | +14 min |
| 2026-04 | 25 | 84% | -1 min |
| 2026-05 | 17 | 65% | +23 min |
| 2026-06 | 1 | 100% | +9 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 13 | 92% |
| Tue | 13 | 85% |
| Wed | 13 | 77% |
| Thu | 13 | 92% |
| Fri | 13 | 77% |
| Sat | 11 | 73% |
| Sun | 12 | 83% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…