About 1 in 6 DL 665 flights from Atlanta arrived 15+ minutes late, diverted or cancelled over the past year (18%); 2.5% were cancelled. The typical flight landed 6 minutes early.
DL 665: ATL → ONT
Scheduled to leave Atlanta at 9:41 a.m. local time. Over the past year it arrived on time 82% of the time (365 flights), in line with other DL flights on the route at that hour (83%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 53 | 85% |
| Tuesday | 52 | 83% |
| Wednesday | 52 | 87% |
| Thursday | 52 | 79% |
| Friday | 52 | 79% |
| Saturday | 52 | 79% |
| Sunday | 52 | 83% |
Why it was late
All flights ATL → ONT · Connecting off DL 665? Check the risk
DL 665: ONT → ATL
Scheduled to leave Ontario at 12:41 p.m. local time. Over the past year it arrived on time 81% of the time (365 flights), in line with other DL flights on the route at that hour (80%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 53 | 74% |
| Tuesday | 52 | 88% |
| Wednesday | 52 | 90% |
| Thursday | 52 | 87% |
| Friday | 52 | 77% |
| Saturday | 52 | 75% |
| Sunday | 52 | 77% |
Why it was late
All flights ONT → ATL · Connecting off DL 665? Check the risk
Questions
How often is DL 665 from ATL to ONT late?
Delta Air Lines 665 from Atlanta, GA to Ontario, CA arrived 15 or more minutes late, was diverted or was cancelled on 18% of 365 scheduled flights between September 2025 and August 2026. 2.5% were cancelled.
How often is DL 665 from ONT to ATL late?
Delta Air Lines 665 from Ontario, CA to Atlanta, GA arrived 15 or more minutes late, was diverted or was cancelled on 19% of 365 scheduled flights between September 2025 and August 2026. 1.6% were cancelled.
Flight numbers change. Figures cover flights with this airline, number and route only. "Likely range" is the 95% interval for the true on-time rate given the number of flights. This is history, not live status: check Delta Air Lines for today's flight. Method.