ON TIMEBOARD

UA 637 on time

United Airlines 637: Washington to Austin at 8:25 a.m. (past 12 months)

On time
92%
254 flights · likely 88–95%
Cancelled
0.8%
of scheduled flights
Typical arrival
−17 min
median vs schedule
When late
+61 min
average delay
Similar flights
92%
UA, same route & hour

About 1 in 12 UA 637 flights from Washington arrived 15+ minutes late, diverted or cancelled over the past year (8%); 0.8% were cancelled. The typical flight landed 17 minutes early.

UA 637: IAD → AUS

Scheduled to leave Washington at 8:25 a.m. local time. Over the past year it arrived on time 92% of the time (254 flights), in line with other UA flights on the route at that hour (92%). Last seen in the data Aug 31, 2026.

Month by month

40%70%100%Sep 2025: 96% on time (26 flights)96SepOct 2025: 93% on time (27 flights)93OctNov 2025: 100% on time (25 flights)100NovDec 2025: 90% on time (29 flights)90DecJan 2026: 89% on time (18 flights)89JanFeb 2026: 90% on time (21 flights)90FebMar 2026: too few flights (6 flights)MarApr 2026: 100% on time (30 flights)100AprMay 2026: 90% on time (20 flights)90MayJun 2026: too few flights (5 flights)JunJul 2026: 85% on time (27 flights)85JulAug 2026: 75% on time (20 flights)75Aug

By day of week

DayFlightsOn time
Monday4584%
Tuesday3294%
Wednesday3597%
Thursday4398%
Friday4393%
Saturday12—
Sunday4486%

Why it was late

Late inbound plane 44%Air traffic & airport (NAS) 41%Airline (crew, maintenance, ops) 11%Severe weather 4%

All flights IAD → AUS · Connecting off UA 637? Check the risk

Questions

How often is UA 637 from IAD to AUS late?

United Airlines 637 from Washington, DC to Austin, TX arrived 15 or more minutes late, was diverted or was cancelled on 8% of 254 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.