Flight OddsUA521 BNA → SFO
United Airlines · Nashville, TN to San Francisco, CA · 31 flights observed, 2025-07-01 to 2025-07-31 · 1,969 mi
UA521 covers more than one route in the data window — the stats below are for BNA → SFO, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
79%
Median delay
-9 min
90th percentile
+31 min
Cancellation rate
10%
How often is UA521 on time?
Across 31 flights on BNA → SFO from 2025-07-01 to 2025-07-31, UA521 arrived within 15 minutes of schedule 79% of the time. The median arrival delay was -9 min, and the worst 10% of flights arrived +31 min or later. 10% of flights were cancelled.
Delay distribution
Arrival delay for completed flights (excludes cancellations and diversions).
| Arrival | Flights | Share |
|---|---|---|
| Early / on-time | 22 | 79% |
| 16-30 min | 3 | 11% |
| 31-60 min | 1 | 4% |
| 61-120 min | 0 | 0% |
| 2+ hrs | 2 | 7% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2025-07 | 28 | 79% | +10 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 4 | 50% |
| Tue | 5 | 80% |
| Wed | 4 | 100% |
| Thu | 5 | 80% |
| Fri | 3 | 100% |
| Sat | 3 | 67% |
| Sun | 4 | 75% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…