About 1 in 6 UA 4427 flights from Washington arrived 15+ minutes late, diverted or cancelled over the past year (18%); 0.8% were cancelled. The typical flight landed 15 minutes early.
UA 4427: IAD → STL
Scheduled to leave Washington at 8:40 a.m. local time, operated by GoJet as G7 4427. Over the past year it arrived on time 82% of the time (266 flights), in line with other UA flights on the route at that hour (81%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 41 | 76% |
| Tuesday | 37 | 86% |
| Wednesday | 36 | 83% |
| Thursday | 40 | 88% |
| Friday | 40 | 80% |
| Saturday | 32 | 84% |
| Sunday | 40 | 80% |
Why it was late
All flights IAD → STL · Connecting off UA 4427? Check the risk
Questions
How often is UA 4427 from IAD to STL late?
United Airlines 4427 from Washington, DC to St. Louis, MO arrived 15 or more minutes late, was diverted or was cancelled on 18% of 266 scheduled flights between September 2025 and August 2026. 0.8% were cancelled.
Flight numbers change. Figures cover flights with this airline, number and route only. "Likely range" is the 95% interval for the true on-time rate given the number of flights. This is history, not live status: check United Airlines for today's flight. Method.