Flight OddsUA4399 STL → ORD
United Airlines · St. Louis, MO to Chicago, IL · 139 flights observed, 2025-07-01 to 2025-12-17 · 258 mi
UA4399 covers more than one route in the data window — the stats below are for STL → ORD, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
68%
Median delay
-8 min
90th percentile
+106 min
Cancellation rate
0%
How often is UA4399 on time?
Across 139 flights on STL → ORD from 2025-07-01 to 2025-12-17, UA4399 arrived within 15 minutes of schedule 68% of the time. The median arrival delay was -8 min, and the worst 10% of flights arrived +106 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 | 95 | 68% |
| 16-30 min | 4 | 3% |
| 31-60 min | 18 | 13% |
| 61-120 min | 10 | 7% |
| 2+ hrs | 12 | 9% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2025-07 | 31 | 77% | +9 min |
| 2025-08 | 31 | 84% | +5 min |
| 2025-09 | 24 | 67% | +41 min |
| 2025-10 | 6 | 67% | +18 min |
| 2025-11 | 30 | 63% | +24 min |
| 2025-12 | 17 | 35% | +52 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 20 | 65% |
| Tue | 21 | 81% |
| Wed | 21 | 48% |
| Thu | 19 | 79% |
| Fri | 19 | 74% |
| Sat | 19 | 53% |
| Sun | 20 | 80% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…