Flight profile · Delta Air Lines
DL859
Boston (BOS) to Salt Lake City (SLC) · scheduled 6:10 AM – 9:43 AM
How DL859 performs
977 operations, 2023-07-01 to 2026-06-30.
DL859 arrived on time 88.0% of the time, against 78.7% for all BOS → SLC flights — this specific departure is 9.3 percentage points better than the route as a whole. Against Delta Air Lines’s own flights on this route it is 5.5 points better.
Source: US DOT Bureau of Transportation Statistics · 977 operations between 2023-07-01 to 2026-06-30
Against the rest of the route
| On time | Cancelled | Median delay | Severe | Flights | |
|---|---|---|---|---|---|
| DL859 | 88.0% | 1.02% | -10 min | 2.4% | 977 |
| Delta Air Lines on BOS → SLC | 82.5% | 0.71% | -8 min | 5.5% | 3,102 |
| All BOS → SLC flights | 78.7% | 0.78% | -7 min | 7.2% | 3,867 |
Source: FlyerIntel analysis of US DOT BTS data · 2023-07-01 to 2026-06-30
By day of week
Does DL859 run worse on particular days?
Monday is historically the most reliable day and Sunday the least, a gap of 7.0 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · 2023-07-01 to 2026-06-30 · Days with fewer than 120 operations are not scored.
Other routes DL859 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 |
|---|---|---|---|
| SLC→PDX Salt Lake City to Portland | 2023-11-05 – 2023-12-15 | 40 | — |
| PDX→SLC Portland to Salt Lake City | 2023-12-07 – 2023-12-15 | 9 | — |
| ATL→ROC Atlanta to Rochester | 2023-09-05 – 2023-11-04 | 17 | — |
| ROC→ATL Rochester to Atlanta | 2023-09-05 – 2023-11-04 | 17 | — |
| LAX→MSP Los Angeles to Minneapolis | 2023-10-09 – 2023-10-27 | 19 | — |
| ATL→IND Atlanta to Indianapolis | 2023-09-10 – 2023-10-08 | 17 | — |
Because the same number has served different journeys, the statistics above describe only the route DL859 currently operates. Blending them would produce an average of two different flights.
Data and methodology
Calculated by FlyerIntel from 977 records of DL859 operating BOS → SLC, 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.