Flight OddsUA4639 BOI → SFO
United Airlines · Boise, ID to San Francisco, CA · 77 flights observed, 2026-03-05 to 2026-05-20 · 522 mi
UA4639 covers more than one route in the data window — the stats below are for BOI → SFO, the one it has flown most recently. The others are linked under “Other routes”.
On-time arrival
48%
Median delay
+18 min
90th percentile
+84 min
Cancellation rate
0%
How often is UA4639 on time?
Across 77 flights on BOI → SFO from 2026-03-05 to 2026-05-20, UA4639 arrived within 15 minutes of schedule 48% of the time. The median arrival delay was +18 min, and the worst 10% of flights arrived +84 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 | 37 | 48% |
| 16-30 min | 10 | 13% |
| 31-60 min | 16 | 21% |
| 61-120 min | 9 | 12% |
| 2+ hrs | 5 | 6% |
Performance by month
| Month | Flights | On-time | Avg delay |
|---|---|---|---|
| 2026-03 | 27 | 85% | +38 min |
| 2026-04 | 30 | 43% | +43 min |
| 2026-05 | 20 | 5% | +57 min |
Performance by day of week
| Day | Flights | On-time |
|---|---|---|
| Mon | 11 | 27% |
| Tue | 11 | 36% |
| Wed | 11 | 55% |
| Thu | 11 | 36% |
| Fri | 11 | 64% |
| Sat | 11 | 73% |
| Sun | 11 | 45% |
Other routes
Related
Based on US Department of Transportation Bureau of Transportation Statistics on-time data. Loading live conditions and full charts…