About 1 in 2 DL 509 flights from Detroit arrived 15+ minutes late, diverted or cancelled over the past year (49%); 0.7% were cancelled. The typical flight landed 11 minutes late.
DL 509: DTW → SFO
Scheduled to leave Detroit at 8:59 p.m. local time. Over the past year it arrived on time 51% of the time (138 flights), in line with other DL flights on the route at that hour (50%). Last seen in the data Aug 2, 2026.
Usually Delta Air Lines's last flight of the day from Detroit to San Francisco (80% of days). Delta Air Lines's last DTW–SFO flight was cancelled 0.8% of the time, against 0.7% for its earlier ones. If it's cancelled, the next Delta Air Lines flight is usually around 8:30 a.m. the next morning.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 24 | 46% |
| Tuesday | 16 | — |
| Wednesday | 14 | — |
| Thursday | 22 | 45% |
| Friday | 24 | 54% |
| Saturday | 12 | — |
| Sunday | 26 | 46% |
Why it was late
All flights DTW → SFO · Connecting off DL 509? Check the risk
Questions
How often is DL 509 from DTW to SFO late?
Delta Air Lines 509 from Detroit, MI to San Francisco, CA arrived 15 or more minutes late, was diverted or was cancelled on 49% of 138 scheduled flights between September 2025 and August 2026. 0.7% 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.