United Airlines DEN to ONT on-time performance
United Airlines nonstop flights from Denver to Ontario · Aug 2025 – Jul 2026
On-time arrivals
80%
arrived < 15 min late
Cancelled
0.0%
0 flights
Avg arrival delay
15 min
68 min when late
Rank on route
#2 of 3
route average 75% on time
Key facts
- United Airlines flights on DEN to ONT arrived on time 80% of the time in Aug 2025 – Jul 2026.
- 0% were cancelled, and 9% arrived an hour or more late.
- That ranks #2 of 3 airlines on this route, which averaged 75% on time overall.
- The largest source of delay minutes was late-arriving aircraft (56%).
On-time trend by month
Why this airline's flights were late
- Late-arriving aircraft56%
- Airline (crew, maintenance, cleaning, fueling)31%
- Air traffic control & airport congestion12%
- Extreme weather1%
- Security0%
Other airlines on DEN to ONT
- Southwest Airlines70% on time · 16 min avg delay
- Frontier Airlines80% on time · 13 min avg delay
Full DEN to ONT comparison →
United Airlines on-time record across all routes →
823 United Airlines flights tracked on this route; 0 cancelled, 1 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.