DL821
DL821 (Delta Air Lines) flies Atlanta to Boston. Of 556 departures recorded from October 2024 to July 2026, 65.8% left on time, according to the US BTS.
- On-time departures65.8%of 556 flights
- Average delay20.7 min
- July 202631▲ 72.2%vs July 2025
- Cancelled1.1%
according to the US BTS · Oct 12, 2024 → Jul 31, 2026 domestic flights only
Recorded departures by month
Partial coverage: domestic flights only · 22 of 22 periods have data
The most recent periods19 periods
| Period | Departures 2025 | Departures 2026 | Change vs last year |
|---|---|---|---|
| January | 12 | 30 | ▲ 150.0% |
| February | 10 | 28 | ▲ 180.0% |
| March | 27 | 31 | ▲ 14.8% |
| April | 22 | 30 | ▲ 36.4% |
| May | 22 | 31 | ▲ 40.9% |
| June | 26 | 30 | ▲ 15.4% |
| July | 18 | 31 | ▲ 72.2% |
| August | 16 | – | – |
| September | 20 | – | – |
| October | 31 | – | in progress |
| November | 29 | – | – |
| December | 31 | – | – |
| Year to date (Jan–Jul) | 137 | 211 | ▲ 54.0% |
according to the US BTS · October 2024 → July 2026
On-time departures by month
Partial coverage: domestic flights only · 22 of 22 periods have data
On time = departure within 15 minutes of schedule. Non-cancelled flights with a recorded delay only.
The most recent periods19 periods
| Period | On time 2025 | On time 2026 | Change vs last year |
|---|---|---|---|
| January | 58.3% | 75.9% | ▲ 30.1% |
| February | 60.0% | 73.1% | ▲ 21.8% |
| March | 81.5% | 67.7% | ▼ 16.9% |
| April | 63.6% | 66.7% | ▲ 4.8% |
| May | 59.1% | 71.0% | ▲ 20.1% |
| June | 46.2% | 80.0% | ▲ 73.3% |
| July | 38.9% | 41.9% | ▲ 7.8% |
| August | 56.3% | – | – |
| September | 60.0% | – | – |
| October | 56.7% | – | in progress |
| November | 75.0% | – | – |
| December | 71.0% | – | – |
| Year-to-date average (Jan–Jul) | 58.2% | 68.0% | ▲ 16.9% |
according to the US BTS · October 2024 → July 2026
Average departure delay by month
Partial coverage: domestic flights only · 22 of 22 periods have data
according to the US BTS · October 2024 → July 2026
Cancelled departures by month
Partial coverage: domestic flights only · 22 of 22 periods have data
The most recent periods19 periods
| Period | Cancelled 2025 | Cancelled 2026 | Change vs last year |
|---|---|---|---|
| January | 0 | 1 | – |
| February | 0 | 2 | – |
| March | 0 | 0 | – |
| April | 0 | 0 | – |
| May | 0 | 0 | – |
| June | 0 | 0 | – |
| July | 0 | 0 | – |
| August | 0 | – | – |
| September | 0 | – | – |
| October | 1 | – | in progress |
| November | 1 | – | – |
| December | 0 | – | – |
| Year to date (Jan–Jul) | 0 | 3 |
according to the US BTS · October 2024 → July 2026
This is not a forecast
This is a historical record of departures already flown, not a forecast for your flight.
Cancellation share
- Not cancelled 98.9% 550
- Cancelled 1.1% 6
Share of all recorded flights in the period, all legs. · Oct 12, 2024 → Jul 31, 2026
Legs flown under this number
1| Routes | Distance (km) | Avg delay | On time | Departures |
|---|---|---|---|---|
| ATL BOS Hartsfield Jackson Atlanta International Airport – Boston Logan International Airport | 1,521 | 20.7 min | 65.8% | 556 |
Monthly figures
| Period | Departures | With departure delay recorded | On time | Cancelled |
|---|---|---|---|---|
| October 2024 | 20 | 20 | 75.0% | 0 |
| November 2024 | 30 | 30 | 80.0% | 0 |
| December 2024 | 31 | 30 | 66.7% | 1 |
| January 2025 | 12 | 12 | 58.3% | 0 |
| February 2025 | 10 | 10 | 60.0% | 0 |
| March 2025 | 27 | 27 | 81.5% | 0 |
| April 2025 | 22 | 22 | 63.6% | 0 |
| May 2025 | 22 | 22 | 59.1% | 0 |
| June 2025 | 26 | 26 | 46.2% | 0 |
| July 2025 | 18 | 18 | 38.9% | 0 |
| August 2025 | 16 | 16 | 56.3% | 0 |
| September 2025 | 20 | 20 | 60.0% | 0 |
| October 2025 | 31 | 30 | 56.7% | 1 |
| November 2025 | 29 | 28 | 75.0% | 1 |
| December 2025 | 31 | 31 | 71.0% | 0 |
| January 2026 | 30 | 29 | 75.9% | 1 |
| February 2026 | 28 | 26 | 73.1% | 2 |
| March 2026 | 31 | 31 | 67.7% | 0 |
| April 2026 | 30 | 30 | 66.7% | 0 |
| May 2026 | 31 | 31 | 71.0% | 0 |
| June 2026 | 30 | 30 | 80.0% | 0 |
| July 2026 | 31 | 31 | 41.9% | 0 |