About 1 in 2 DL 5851 flights from Boston arrived 15+ minutes late, diverted or cancelled over the past year (45%); 7.5% were cancelled. The typical flight landed 1 minutes early.
DL 5851: BOS → BWI
Scheduled to leave Boston at 8:35 p.m. local time, operated by Republic Airways as YX 5851. Over the past year it arrived on time 55% of the time (133 flights), in line with other DL flights on the route at that hour (54%). Last seen in the data Aug 31, 2026.
Usually Delta Air Lines's last flight of the day from Boston to Baltimore (100% of days). Delta Air Lines's last BOS–BWI flight was cancelled 6.3% of the time, against 3.4% for its earlier ones. If it's cancelled, the next Delta Air Lines flight is usually around 6:35 a.m. the next morning.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 23 | 52% |
| Tuesday | 22 | 55% |
| Wednesday | 22 | 68% |
| Thursday | 22 | 55% |
| Friday | 22 | 50% |
| Sunday | 22 | 50% |
Why it was late
All flights BOS → BWI · Connecting off DL 5851? Check the risk
Questions
How often is DL 5851 from BOS to BWI late?
Delta Air Lines 5851 from Boston, MA to Baltimore, MD arrived 15 or more minutes late, was diverted or was cancelled on 45% of 133 scheduled flights between September 2025 and August 2026. 7.5% 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.