Flight Reliability
UA 391 · United Airlines
San Francisco → Austin (SFO–AUS)
96
Nerd Approved
WanderNerd Reliability Score
- 88%
- Arrive within 15 minutes
- 2 min
- Average arrival delay
- 0%
- Cancelled
- 1 min
- Median arrival delay
Based on 68 historical flights. Data through May 2026.
What the data says
Friday is doing you no favors.
UA 391 arrived on time 90% of the time on Tuesdays and just 70% on Fridays. That gap is worth planning around.
Better than the SFO–AUS route average.
UA 391 arrived on time 88% of the time, versus 77% across the SFO–AUS route.
Better than the United Airlines network average.
UA 391 arrived on time 88% of the time, versus 79% across the United Airlines network.
The breakdown
- Mon—(9 flights)
- Tue90%(10 flights)
- Wed80%(10 flights)
- Thu90%(10 flights)
- Fri70%(10 flights)
- Sat90%(10 flights)
- Sun—(9 flights)
88%
Oct
Aug 92% → Oct 88% on time
| Month | On-time percentage | Flights |
|---|---|---|
| August 2025 | 92% | 13 |
| September 2025 | 87% | 30 |
| October 2025 | 88% | 25 |
- Departures on time
- 91%
- Diverted
- 0%
- Flights flown
- 68
- Months covered
- 3
Same route, other flights
Keep nerding
Based on 68 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.