ON TIMEBOARD

UA 1535 on time

United Airlines 1535: Washington to Houston at 12:50 p.m.; Houston to Dallas at 6:05 p.m.; Raleigh to Washington at 10:32 a.m. (past 12 months). Figures below the title are for IAD → IAH, its busiest leg

On time
84%
320 flights · likely 80–88%
Cancelled
0.6%
of scheduled flights
Typical arrival
−12 min
median vs schedule
When late
+85 min
average delay
Similar flights
86%
UA, same route & hour

About 1 in 6 UA 1535 flights from Washington arrived 15+ minutes late, diverted or cancelled over the past year (16%); 0.6% were cancelled. The typical flight landed 12 minutes early.

UA 1535: IAD → IAH

Scheduled to leave Washington at 12:50 p.m. local time. Over the past year it arrived on time 84% of the time (320 flights), in line with other UA flights on the route at that hour (86%). Last seen in the data Aug 31, 2026.

Month by month

40%70%100%Sep 2025: too few flights (6 flights)SepOct 2025: 77% on time (31 flights)77OctNov 2025: 87% on time (30 flights)87NovDec 2025: 77% on time (31 flights)77DecJan 2026: 94% on time (31 flights)94JanFeb 2026: too few flights (11 flights)FebMar 2026: 78% on time (27 flights)78MarApr 2026: 97% on time (30 flights)97AprMay 2026: 87% on time (31 flights)87MayJun 2026: 70% on time (30 flights)70JunJul 2026: 77% on time (31 flights)77JulAug 2026: 90% on time (31 flights)90Aug

By day of week

DayFlightsOn time
Monday4689%
Tuesday4589%
Wednesday4580%
Thursday4680%
Friday4676%
Saturday4685%
Sunday4689%

Why it was late

Late inbound plane 43%Air traffic & airport (NAS) 29%Airline (crew, maintenance, ops) 22%Severe weather 5%

All flights IAD → IAH · Connecting off UA 1535? Check the risk

UA 1535: IAH → DFW

Scheduled to leave Houston at 6:05 p.m. local time. Over the past year it arrived on time 68% of the time (217 flights), in line with other UA flights on the route at that hour (68%). Last seen in the data Aug 31, 2026.

Month by month

40%70%100%Dec 2025: too few flights (13 flights)DecJan 2026: too few flights (5 flights)JanFeb 2026: 88% on time (17 flights)88FebMar 2026: 68% on time (31 flights)68MarApr 2026: 80% on time (30 flights)80AprMay 2026: 65% on time (31 flights)65MayJun 2026: 50% on time (30 flights)50JunJul 2026: 58% on time (31 flights)58JulAug 2026: 62% on time (29 flights)62Aug

By day of week

DayFlightsOn time
Monday3272%
Tuesday3063%
Wednesday2969%
Thursday3272%
Friday3181%
Saturday3165%
Sunday3253%

Why it was late

Late inbound plane 49%Air traffic & airport (NAS) 30%Airline (crew, maintenance, ops) 17%Severe weather 4%

All flights IAH → DFW · Connecting off UA 1535? Check the risk

UA 1535: RDU → IAD

Scheduled to leave Raleigh at 10:32 a.m. local time. Over the past year it arrived on time 89% of the time (180 flights), in line with other UA flights on the route at that hour (90%). Last seen in the data Aug 31, 2026.

Month by month

40%70%100%Mar 2026: 89% on time (27 flights)89MarApr 2026: 97% on time (30 flights)97AprMay 2026: 100% on time (31 flights)100MayJun 2026: 90% on time (30 flights)90JunJul 2026: 68% on time (31 flights)68JulAug 2026: 94% on time (31 flights)94Aug

By day of week

DayFlightsOn time
Monday2692%
Tuesday2592%
Wednesday2588%
Thursday2688%
Friday2688%
Saturday2692%
Sunday2685%

Why it was late

Late inbound plane 59%Airline (crew, maintenance, ops) 31%Air traffic & airport (NAS) 10%

All flights RDU → IAD · Connecting off UA 1535? Check the risk

Questions

How often is UA 1535 from IAD to IAH late?

United Airlines 1535 from Washington, DC to Houston, TX arrived 15 or more minutes late, was diverted or was cancelled on 16% of 320 scheduled flights between September 2025 and August 2026. 0.6% were cancelled.

How often is UA 1535 from IAH to DFW late?

United Airlines 1535 from Houston, TX to Dallas/Fort Worth, TX arrived 15 or more minutes late, was diverted or was cancelled on 32% of 217 scheduled flights between September 2025 and August 2026. 0.5% were cancelled.

How often is UA 1535 from RDU to IAD late?

United Airlines 1535 from Raleigh/Durham, NC to Washington, DC arrived 15 or more minutes late, was diverted or was cancelled on 11% of 180 scheduled flights between September 2025 and August 2026. 0.6% 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.