About 1 in 8 DL 521 flights from Los Angeles arrived 15+ minutes late, diverted or cancelled over the past year (12%); 1.7% were cancelled. The typical flight landed 8 minutes early.
DL 521: LAX → DFW
Scheduled to leave Los Angeles at 7:35 a.m. local time. Over the past year it arrived on time 88% of the time (353 flights), in line with other DL flights on the route at that hour (87%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 52 | 85% |
| Tuesday | 51 | 88% |
| Wednesday | 51 | 90% |
| Thursday | 51 | 80% |
| Friday | 51 | 92% |
| Saturday | 48 | 85% |
| Sunday | 49 | 92% |
Why it was late
All flights LAX → DFW · Connecting off DL 521? Check the risk
Questions
How often is DL 521 from LAX to DFW late?
Delta Air Lines 521 from Los Angeles, CA to Dallas/Fort Worth, TX arrived 15 or more minutes late, was diverted or was cancelled on 12% of 353 scheduled flights between September 2025 and August 2026. 1.7% 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.