Flight OddsUnited Airlines · Washington, DC to Philadelphia, PA · 116 flights observed, 2025-07-01 to 2025-10-24 · 135 mi
UA4539 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”.
How often is UA4539 on time?
Across 116 flights on IAD → PHL from 2025-07-01 to 2025-10-24, UA4539 arrived within 15 minutes of schedule 72% of the time. The median arrival delay was -1 min, and the worst 10% of flights arrived +142 min or later. 5% of flights were cancelled.
Delay distribution
Arrival delay for completed flights (excludes cancellations and diversions).
| Arrival | Flights | Share |
|---|---|---|
| Early / on-time | 79 | 72% |
| 16-30 min | 1 | 1% |
| 31-60 min | 8 | 7% |
| 61-120 min | 10 | 9% |
| 2+ hrs | 12 | 11% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2025-07 | 26 | 58% | +52 min |
| 2025-08 | 31 | 65% | +41 min |
| 2025-09 | 29 | 83% | +18 min |
| 2025-10 | 24 | 83% | +16 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 15 | 67% |
| Tue | 15 | 100% |
| Wed | 17 | 53% |
| Thu | 16 | 63% |
| Fri | 17 | 82% |
| Sat | 15 | 73% |
| Sun | 15 | 67% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…