About 1 in 3 DL 821 flights from Atlanta arrived 15+ minutes late, diverted or cancelled over the past year (32%); 1.4% were cancelled. The typical flight landed 2 minutes late.
DL 821: ATL → BOS
Scheduled to leave Atlanta at 6:15 p.m. local time. Over the past year it arrived on time 68% of the time (349 flights), in line with other DL flights on the route at that hour (67%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 51 | 67% |
| Tuesday | 50 | 68% |
| Wednesday | 50 | 72% |
| Thursday | 50 | 64% |
| Friday | 51 | 76% |
| Saturday | 50 | 72% |
| Sunday | 47 | 57% |
Why it was late
All flights ATL → BOS · Connecting off DL 821? Check the risk
Questions
How often is DL 821 from ATL to BOS late?
Delta Air Lines 821 from Atlanta, GA to Boston, MA arrived 15 or more minutes late, was diverted or was cancelled on 32% of 349 scheduled flights between September 2025 and August 2026. 1.4% 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.