Southwest Airlines ONT to DEN on-time performance
Southwest Airlines nonstop flights from Ontario to Denver · Aug 2025 – Jul 2026
On-time arrivals
76%
arrived < 15 min late
Cancelled
0.3%
4 flights
Avg arrival delay
14 min
53 min when late
Rank on route
#3 of 3
route average 81% on time
Key facts
- Southwest Airlines flights on ONT to DEN arrived on time 76% of the time in Aug 2025 – Jul 2026.
- 0.3% were cancelled, and 7% arrived an hour or more late.
- That ranks #3 of 3 airlines on this route, which averaged 81% on time overall.
- The largest source of delay minutes was air traffic control & airport congestion (41%).
On-time trend by month
Why this airline's flights were late
- Air traffic control & airport congestion41%
- Late-arriving aircraft36%
- Airline (crew, maintenance, cleaning, fueling)20%
- Extreme weather2%
- Security1%
Other airlines on ONT to DEN
- United Airlines87% on time · 12 min avg delay
- Frontier Airlines84% on time · 16 min avg delay
Full ONT to DEN comparison →
Southwest Airlines on-time record across all routes →
1,268 Southwest Airlines flights tracked on this route; 4 cancelled, 5 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.