United Airlines ONT to DEN on-time performance
United Airlines nonstop flights from Ontario to Denver · Aug 2025 – Jul 2026
On-time arrivals
87%
arrived < 15 min late
Cancelled
0.4%
3 flights
Avg arrival delay
12 min
87 min when late
Rank on route
#1 of 3
route average 81% on time
Key facts
- United Airlines flights on ONT to DEN arrived on time 87% of the time in Aug 2025 – Jul 2026.
- 0.4% were cancelled, and 6% arrived an hour or more late.
- That ranks #1 of 3 airlines on this route, which averaged 81% on time overall.
- The largest source of delay minutes was late-arriving aircraft (49%).
On-time trend by month
Why this airline's flights were late
- Late-arriving aircraft49%
- Airline (crew, maintenance, cleaning, fueling)25%
- Air traffic control & airport congestion23%
- Extreme weather3%
- Security0%
Other airlines on ONT to DEN
- Southwest Airlines76% on time · 14 min avg delay
- Frontier Airlines84% on time · 16 min avg delay
Full ONT to DEN comparison →
United Airlines on-time record across all routes →
823 United Airlines flights tracked on this route; 3 cancelled, 2 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.