Tracked live by the FAA, but its flight plan was first seen after takeoff, so we don't know the scheduled time and can't say whether it's late.

DELTA · FLIGHT DL 1580 LANDED 8:49 AM ET, ~6 MIN LATE · SCHEDULED TIME UNKNOWN
Yesterday

DL 1580 · BOS → IAD

took off 7:41 AM ET · landed 8:49 AM ET (scheduled time unknown)
Forecast issued Tue 10:00 PM ET · 14h after departure

Odds over time

Arrive at IAD more than 15 minutes late?
13% chance · ±0 pts +1 pt · 24h
HOW SURE WE ARE Very high. The odds now come almost entirely from live conditions.
WEATHER FORECASTS LIVE IN THE AIR 0% 5% 10% 15% 20% 2.9d 2d 1d 12h 6h Departs Lands