About 1 in 4 UA 1240 flights from Dallas arrived 15+ minutes late, diverted or cancelled over the past year (23%); 1.2% were cancelled. The typical flight landed 4 minutes early.
UA 1240: DFW → IAD
Scheduled to leave Dallas at 5:15 p.m. local time. Over the past year it arrived on time 77% of the time (328 flights), in line with other UA flights on the route at that hour (77%). Last seen in the data Aug 31, 2026.
Usually United Airlines's last flight of the day from Dallas to Washington (100% of days). United Airlines's last DFW–IAD flight was cancelled 1.1% of the time, against 1.0% for its earlier ones. If it's cancelled, the next United Airlines flight is usually around 7:20 a.m. the next morning.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 45 | 78% |
| Tuesday | 44 | 80% |
| Wednesday | 50 | 84% |
| Thursday | 48 | 75% |
| Friday | 48 | 79% |
| Saturday | 44 | 75% |
| Sunday | 49 | 65% |
Why it was late
All flights DFW → IAD · Connecting off UA 1240? Check the risk
Questions
How often is UA 1240 from DFW to IAD late?
United Airlines 1240 from Dallas/Fort Worth, TX to Washington, DC arrived 15 or more minutes late, was diverted or was cancelled on 23% of 328 scheduled flights between September 2025 and August 2026. 1.2% 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.