Flight OddsUA503 BOS → ORD
United Airlines · Boston, MA to Chicago, IL · 108 flights observed, 2026-03-06 to 2026-06-30 · 867 mi
UA503 covers more than one route in the data window — the stats below are for BOS → ORD, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
84%
Median delay
-10 min
90th percentile
+39 min
Cancellation rate
0%
How often is UA503 on time?
Across 108 flights on BOS → ORD from 2026-03-06 to 2026-06-30, UA503 arrived within 15 minutes of schedule 84% of the time. The median arrival delay was -10 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 | 91 | 84% |
| 16-30 min | 5 | 5% |
| 31-60 min | 2 | 2% |
| 61-120 min | 6 | 6% |
| 2+ hrs | 4 | 4% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2026-03 | 26 | 73% | +78 min |
| 2026-04 | 30 | 90% | -1 min |
| 2026-05 | 26 | 85% | -7 min |
| 2026-06 | 26 | 88% | +3 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 17 | 82% |
| Tue | 17 | 82% |
| Wed | 16 | 94% |
| Thu | 16 | 81% |
| Fri | 17 | 76% |
| Sat | 8 | 100% |
| Sun | 17 | 82% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…