Flight profile · Delta Air Lines
DL321
Boston (BOS) to Los Angeles (LAX) · scheduled 8:35 PM – 11:52 PM
How DL321 performs
548 operations, 2024-06-07 to 2026-06-26.
DL321 arrived on time 70.1% of the time, against 77.5% for all BOS → LAX flights — this specific departure is 7.4 percentage points worse than the route as a whole. Against Delta Air Lines’s own flights on this route it is 7.8 points worse.
Source: US DOT Bureau of Transportation Statistics · 548 operations between 2024-06-07 to 2026-06-26
Against the rest of the route
| On time | Cancelled | Median delay | Severe | Flights | |
|---|---|---|---|---|---|
| DL321 | 70.1% | 1.46% | -1 min | 11.5% | 548 |
| Delta Air Lines on BOS → LAX | 77.9% | 0.89% | -5 min | 7.6% | 3,492 |
| All BOS → LAX flights | 77.5% | 0.76% | -7 min | 8.3% | 13,833 |
Source: FlyerIntel analysis of US DOT BTS data · 2024-06-07 to 2026-06-26
Other routes DL321 has flown
A flight number is a slot in a schedule, and carriers reassign it. These are the other city pairs this number served in the analysis period.
| Route | Operated | Flights | On time |
|---|---|---|---|
| DEN→ATL Denver to Atlanta | 2025-06-14 – 2025-07-05 | 4 | — |
| CAE→ATL Columbia to Atlanta | 2025-05-10 – 2025-06-07 | 5 | — |
| ATL→CAE Atlanta to Columbia | 2025-05-07 – 2025-06-04 | 9 | — |
| ORD→MSP Chicago to Minneapolis | 2025-05-25 – 2025-05-25 | 1 | — |
| ATL→BWI Atlanta to Baltimore | 2024-12-06 – 2024-12-17 | 12 | — |
| ATL→JFK Atlanta to New York | 2024-05-07 – 2024-06-06 | 31 | — |
| BNA→LAX Nashville to Los Angeles | 2024-04-11 – 2024-05-06 | 16 | — |
| LAS→DTW Las Vegas to Detroit | 2024-04-09 – 2024-05-04 | 12 | — |
| JFK→LAS New York to Las Vegas | 2024-03-10 – 2024-04-08 | 30 | — |
| LGA→ATL New York to Atlanta | 2024-01-08 – 2024-03-08 | 53 | — |
| LAS→JFK Las Vegas to New York | 2023-09-05 – 2024-01-07 | 111 | 89.2% |
| LGA→SAV New York to Savannah | 2023-12-24 – 2023-12-31 | 2 | — |
| SAV→LGA Savannah to New York | 2023-12-24 – 2023-12-31 | 2 | — |
| DTW→SLC Detroit to Salt Lake City | 2023-07-01 – 2023-09-04 | 46 | — |
Because the same number has served different journeys, the statistics above describe only the route DL321 currently operates. Blending them would produce an average of two different flights.
Data and methodology
Calculated by FlyerIntel from 548 records of DL321 operating BOS → LAX, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule. Cancelled and diverted flights are excluded from the on-time rate and reported separately. Flight numbers are resolved as carrier plus number plus route, because the same number serves different routes over time.