Flight OddsUA721 ORD → BOS
United Airlines · Chicago, IL to Boston, MA · 42 flights observed, 2025-07-01 to 2025-08-18 · 867 mi
UA721 covers more than one route in the data window — the stats below are for ORD → BOS, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
81%
Median delay
-7 min
90th percentile
+42 min
Cancellation rate
0%
How often is UA721 on time?
Across 42 flights on ORD → BOS from 2025-07-01 to 2025-08-18, UA721 arrived within 15 minutes of schedule 81% of the time. The median arrival delay was -7 min, and the worst 10% of flights arrived +42 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 | 34 | 81% |
| 16-30 min | 1 | 2% |
| 31-60 min | 4 | 10% |
| 61-120 min | 3 | 7% |
| 2+ hrs | 0 | 0% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2025-07 | 27 | 81% | +4 min |
| 2025-08 | 15 | 80% | +3 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 7 | 71% |
| Tue | 7 | 86% |
| Wed | 7 | 100% |
| Thu | 7 | 71% |
| Fri | 7 | 71% |
| Sat | No data | — |
| Sun | 7 | 86% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…