Flight profile · Delta Air Lines
DL1861
Atlanta (ATL) to San Juan (SJU) · scheduled 6:55 PM – 11:46 PM
How DL1861 performs
1,035 operations, 2023-07-01 to 2026-06-30.
DL1861 arrived on time 69.4% of the time, against 75.0% for all ATL → SJU flights — this specific departure is 5.6 percentage points worse than the route as a whole. Against Delta Air Lines’s own flights on this route it is 9.5 points worse.
Source: US DOT Bureau of Transportation Statistics · 1,035 operations between 2023-07-01 to 2026-06-30
Against the rest of the route
| On time | Cancelled | Median delay | Severe | Flights | |
|---|---|---|---|---|---|
| DL1861 | 69.4% | 0.77% | 0 min | 10.2% | 1,035 |
| Delta Air Lines on ATL → SJU | 78.8% | 0.56% | -2 min | 5.7% | 4,855 |
| All ATL → SJU flights | 75.0% | 0.82% | -1 min | 7.7% | 6,440 |
Source: FlyerIntel analysis of US DOT BTS data · 2023-07-01 to 2026-06-30
By day of week
Does DL1861 run worse on particular days?
Tuesday is historically the most reliable day and Thursday the least, a gap of 11.0 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.
Why DL1861 runs late
Where US DOT attributed the delay minutes on this flight.
crew, maintenance, boarding, fuelling — within the carrier’s control
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for DL1861 on ATL → SJU. A single late flight can carry more than one cause, and only delays of fifteen minutes or more are attributed at all.
Other departures on ATL → SJU
Same airports, same journey — and not the same odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| DL1946 | Delta Air Lines | 83.2% | 3 min early | 1,033 |
| DL1882 | Delta Air Lines | 78.0% | 1 min late | 1,035 |
Every departure listed carries at least 600 operations, so the comparison is between figures that mean something. Schedules change; confirm the departure still operates before booking around this.
Data and methodology
Calculated by FlyerIntel from 1,035 records of DL1861 operating ATL → SJU, 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.
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