Most delayed flights from ONT: every route ranked

17 regularly flown nonstop routes from Ontario International Airport, worst on-time record first (Aug 2025 – Jul 2026). Routes with fewer than 360 flights in the period are listed separately.

#	Destination	On time	Cancelled	Avg delay	Airlines	Flights
1	ONT → SFO San Francisco, CA	62%	0.8%	26 min	3	1,309
2	ONT → HOU Houston, TX	65%	0.0%	17 min	1	362
3	ONT → DAL Dallas, TX	74%	1.5%	14 min	1	399
4	ONT → LAS Las Vegas, NV	77%	0.9%	15 min	2	2,476
5	ONT → DFW Dallas/Fort Worth, TX	79%	2.7%	21 min	2	2,297
6	ONT → DEN Denver, CO	81%	0.3%	14 min	3	2,643
7	ONT → PHX Phoenix, AZ	82%	0.6%	13 min	4	3,027
8	ONT → IAH Houston, TX	85%	1.1%	13 min	2	561
9	ONT → SJC San Jose, CA	86%	0.1%	9 min	1	1,319
10	ONT → SMF Sacramento, CA	86%	0.3%	8 min	1	2,114
11	ONT → SEA Seattle, WA	86%	1.1%	10 min	4	2,505
12	ONT → OAK Oakland, CA	86%	0.4%	8 min	1	1,471
13	ONT → HNL Honolulu, HI	87%	0.2%	8 min	2	423
14	ONT → ATL Atlanta, GA	89%	1.8%	11 min	1	937
15	ONT → PDX Portland, OR	90%	0.7%	7 min	3	565
16	ONT → MDW Chicago, IL	90%	0.3%	5 min	1	360
17	ONT → SLC Salt Lake City, UT	92%	0.9%	8 min	3	1,239

Less frequent routes

Too few flights for a reliable ranking.

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.