Connect in the morning. The same one-hour layover misses 15% of the time at 9 am and almost half the time at 7 pm.
Nonstops (seasonal or thin)
Nonstop details →| Delta | ATL | ONT | 4h 31m | 76% | 1.7% | 937 | 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 Atlanta). Layovers up to 4 hours. Pick a connection for the details.
| Delta + Alaskatwo ticketsDetails → | ATL 08:30 → PDX 10:30DL 539 | 4h 00m Portland | PDX 14:30 → ONT 16:52AS 2093 · flown by Horizon | 11h 22m | 100% | 90% |
| Southwest + Unitedtwo ticketsDetails → | ATL 06:25 → DEN 07:30WN 2114 | 3h 55m Denver | DEN 11:25 → ONT 12:47UA 430 | 9h 22m | 100% | 88% |
| DeltaDetails → | ATL 17:55 → SLC 19:58DL 653 | 3h 01m Salt Lake City | SLC 22:59 → ONT 23:48DL 1614 | 8h 53m | 98% | 87% |
| DeltaDetails → | ATL 10:05 → SLC 12:10DL 387 | 3h 35m Salt Lake City | SLC 15:45 → ONT 16:41DL 4443 · flown by SkyWest | 9h 36m | 100% | 87% |
| DeltaDetails → | ATL 09:52 → SEA 12:20DL 774 | 2h 15m Seattle | SEA 14:35 → ONT 17:19DL 4031 · flown by SkyWest | 10h 27m | 98% | 86% |
| DeltaDetails → | ATL 14:32 → SEA 16:49DL 481 | 3h 01m Seattle | SEA 19:50 → ONT 22:41DL 3884 · flown by SkyWest | 11h 09m | 99% | 83% |
| DeltaDetails → | ATL 08:15 → SLC 10:15DL 830 | 1h 04m Salt Lake City | SLC 11:19 → ONT 12:10DL 3172 | 6h 55m | 91% | 82% |
| SouthwestDetails → | ATL 06:10 → LAS 07:15WN 209 | 1h 50m Las Vegas | LAS 09:05 → ONT 10:10WN 4179 | 7h 00m | 100% | 82% |
| Tight connection: often missed | ||||||
| AmericanDetails → | ATL 08:22 → DFW 09:54AA 1567 | 46m Dallas-Fort Worth | DFW 10:40 → ONT 11:45AA 2242 | 6h 23m | 68% | 49% |
| DeltaDetails → | ATL 16:45 → SEA 19:04DL 472 | 46m Seattle | SEA 19:50 → ONT 22:41DL 3884 · flown by SkyWest | 8h 56m | 54% | 45% |
| SouthwestDetails → | ATL 18:20 → DEN 19:40WN 3002 | 1h 35m Denver | DEN 21:15 → ONT 22:35WN 1663 | 7h 15m | 60% | 21% |
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