Flight OddsUA4538 IAD → PHL
United Airlines · Washington, DC to Philadelphia, PA · 95 flights observed, 2025-07-01 to 2025-10-25 · 135 mi
UA4538 covers more than one route in the data window — the stats below are for IAD → PHL, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
80%
Median delay
-7 min
90th percentile
+35 min
Cancellation rate
0%
How often is UA4538 on time?
Across 95 flights on IAD → PHL from 2025-07-01 to 2025-10-25, UA4538 arrived within 15 minutes of schedule 80% of the time. The median arrival delay was -7 min, and the worst 10% of flights arrived +35 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 | 76 | 80% |
| 16-30 min | 7 | 7% |
| 31-60 min | 7 | 7% |
| 61-120 min | 0 | 0% |
| 2+ hrs | 5 | 5% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2025-07 | 23 | 70% | +14 min |
| 2025-08 | 22 | 86% | +8 min |
| 2025-09 | 29 | 86% | +2 min |
| 2025-10 | 21 | 76% | +11 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 16 | 56% |
| Tue | 16 | 88% |
| Wed | 15 | 73% |
| Thu | 12 | 75% |
| Fri | 17 | 94% |
| Sat | 10 | 100% |
| Sun | 9 | 78% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…