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D

Ontario (ONT) departure delays

2,304 departures · 24 routes · March 2025 – August 2026

73.7%

Left on time

Within 15 minutes of schedule

1%

Cancelled

Share of departures

58 min

When late, late by

Average delayed departure

#87

Rank

Among graded US airports

What the record says about ONT

Departures from Ontario run late more often than average — enough that a tight connection at the far end deserves a second look.

The airlines flying from here are not equally affected. Alaska Airlines left on time 15.3 points more often than Frontier Airlines from the same airport — which is the clearest evidence available that a delayed departure is not purely the airport's fault.

Which airlines run best out of ONT

Airline Departures On time
Alaska Airlines 201 82.8%
American Airlines 296 81.2%
Southwest Airlines 1,007 73.3%
Frontier Airlines 238 67.5%

Routes out of ONT

ONT → DEN Denver 250 flights · 77.42% on time C ONT → SEA Seattle 240 flights · 84.39% on time B ONT → PHX Phoenix 224 flights · 78.28% on time C ONT → DFW Dallas/Fort Worth 210 flights · 75.88% on time D ONT → LAS Las Vegas 206 flights · 68.63% on time D ONT → SMF Sacramento 177 flights · 76.84% on time C ONT → SFO San Francisco 120 flights · 33.33% on time F ONT → SJC San Jose 114 flights · 75.44% on time C ONT → SLC Salt Lake City 113 flights · 96.46% on time A ONT → OAK Oakland 111 flights · 75.68% on time C ONT → ATL Atlanta 80 flights · 92.21% on time — ONT → IAH Houston 60 flights · 77.19% on time — ONT → HNL Honolulu 57 flights · 91.23% on time — ONT → PDX Portland 51 flights · 96.08% on time — ONT → JFK New York 30 flights · 68.97% on time — ONT → CLT Charlotte 30 flights · 80% on time — ONT → MDW Chicago 30 flights · 80% on time — ONT → HOU Houston 30 flights · 53.33% on time — ONT → DAL Dallas 30 flights · 66.67% on time — ONT → BWI Baltimore 30 flights · 100% on time — ONT → BNA Nashville 30 flights · 67.86% on time — ONT → AUS Austin 30 flights · 70% on time — ONT → ORD Chicago 30 flights · 86.21% on time — ONT → STS Santa Rosa 21 flights · 80.95% on time —