United Airlines SFO to ONT on-time performance
United Airlines nonstop flights from San Francisco to Ontario · Aug 2025 – Jul 2026
On-time arrivals
81%
arrived < 15 min late
Cancelled
0.3%
3 flights
Avg arrival delay
11 min
52 min when late
Rank on route
#1 of 3
route average 76% on time
Key facts
- United Airlines flights on SFO to ONT arrived on time 81% of the time in Aug 2025 – Jul 2026.
- 0.3% were cancelled, and 4% arrived an hour or more late.
- That ranks #1 of 3 airlines on this route, which averaged 76% on time overall.
- The largest source of delay minutes was late-arriving aircraft (48%).
On-time trend by month
Why this airline's flights were late
- Late-arriving aircraft48%
- Airline (crew, maintenance, cleaning, fueling)33%
- Air traffic control & airport congestion20%
- Extreme weather0%
- Security0%
Other airlines on SFO to ONT
- Frontier Airlines56% on time · 42 min avg delay
- SkyWest Airlines68% on time · 24 min avg delay
Full SFO to ONT comparison →
United Airlines on-time record across all routes →
982 United Airlines flights tracked on this route; 3 cancelled, 0 diverted.
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. How we calculate this.