The best bet has a stop: Southwest via Phoenix (7h 20m) reaches Ontario on time 84% of the time, against 64% on the nonstop.
Nonstops (seasonal or thin)
Nonstop details →| Southwest | BWI | ONT | 5h 30m | 64% | 0.4% | 281 | Flying now |
Best connections, any airlines
Ranked by chance you reach Ontario on time. Total trip = scheduled departure to arrival, layover included (Ontario is 3 h behind Baltimore). Layovers up to 4 hours. Pick a connection for the details.
| Southwest + Unitedtwo ticketsDetails → | BWI 06:05 → DEN 07:50WN 4436 | 3h 35m Denver | DEN 11:25 → ONT 12:47UA 430 | 9h 42m | 100% | 88% |
| SouthwestDetails → | BWI 07:00 → PHX 08:50WN 1049 | 1h 15m Phoenix | PHX 10:05 → ONT 11:20WN 431 | 7h 20m | 95% | 84% |
| DeltaDetails → | BWI 07:10 → SLC 09:49DL 1176 | 1h 30m Salt Lake City | SLC 11:19 → ONT 12:10DL 3172 | 8h 00m | 93% | 84% |
| SouthwestDetails → | BWI 06:25 → LAS 08:25WN 973 | 3h 05m Las Vegas | LAS 11:30 → ONT 12:32WN 2298 | 9h 07m | 100% | 82% |
| DeltaDetails → | BWI 05:40 → ATL 07:31DL 2950 | 1h 44m Atlanta | ATL 09:15 → ONT 10:40DL 665 | 8h 00m | 97% | 78% |
| Southwest + Frontiertwo ticketsDetails → | BWI 09:35 → LAS 11:35WN 974 | 2h 24m Las Vegas | LAS 13:59 → ONT 15:09F9 1357 | 8h 34m | 94% | 77% |
| UnitedDetails → | BWI 15:03 → IAH 17:19UA 2095 | 3h 12m Houston | IAH 20:31 → ONT 21:55UA 1563 | 9h 52m | 97% | 77% |
| AlaskaDetails → | BWI 16:19 → PDX 18:56AS 1369 | 2h 34m Portland | PDX 21:30 → ONT 23:51AS 97 | 10h 32m | 94% | 77% |
| Tight connection: often missed | ||||||
| SouthwestDetails → | BWI 15:48 → LAS 17:48WN 1102 | 1h 22m Las Vegas | LAS 19:10 → ONT 20:10WN 208 | 7h 22m | 75% | 40% |
| AmericanDetails → | BWI 19:17 → DFW 21:42AA 1626 | 1h 13m Dallas-Fort Worth | DFW 22:55 → ONT 23:59 +1AA 1534 | 7h 45m | 73% | 26% |
Same layover, different day-part
How often the first flight arrives too late to connect (45 min minimum), for one-ticket layovers of 45–80 minutes.
Delays build through the day, so an afternoon first leg eats the layover. A short connection is fine early in the morning and a gamble later on.
Mixing airlines
The table above includes two-ticket connections (marked “two tickets”), held to the 90-minute minimum. One ticket only →
Regional partners count as the airline that sells them: SkyWest flying Delta Connection is one Delta ticket.
About this data: US DOT on-time records, Aug 2025 – Jul 2026, all US airlines; regional flights count under the airline that sells them. Schedules (which flights and connections exist, and their times) are as of Jun 6 – Jul 31, 2026; seasonal flights outside that window aren’t ranked. Rebuilt monthly. JSON