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United Airlines / IAD → SFO

UA 1434 on time

United Airlines 1434: Washington to San Francisco at 12:35 p.m.; Jacksonville to Washington at 9:20 a.m. (past 12 months). Figures below the title are for IAD → SFO, its busiest leg

On time
77%
328 flights · likely 72–81%
Cancelled
0.3%
of scheduled flights
Typical arrival
−4 min
median vs schedule
When late
+68 min
average delay
Similar flights
78%
UA, same route & hour

About 1 in 4 UA 1434 flights from Washington arrived 15+ minutes late, diverted or cancelled over the past year (23%); 0.3% were cancelled. The typical flight landed 4 minutes early.

UA 1434: IAD → SFO

Scheduled to leave Washington at 12:35 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 (78%). Last seen in the data Aug 31, 2026.

Month by month

40%70%100%Sep 2025: 97% on time (30 flights)97SepOct 2025: 94% on time (31 flights)94OctNov 2025: 80% on time (30 flights)80NovDec 2025: 55% on time (31 flights)55DecJan 2026: too few flights (5 flights)JanFeb 2026: 71% on time (17 flights)71FebMar 2026: 81% on time (31 flights)81MarApr 2026: 70% on time (30 flights)70AprMay 2026: 87% on time (31 flights)87MayJun 2026: 63% on time (30 flights)63JunJul 2026: 74% on time (31 flights)74JulAug 2026: 81% on time (31 flights)81Aug

By day of week

DayFlightsOn time
Monday4873%
Tuesday4680%
Wednesday4680%
Thursday4781%
Friday4779%
Saturday4777%
Sunday4770%

Why it was late

Air traffic & airport (NAS) 55%Airline (crew, maintenance, ops) 23%Late inbound plane 19%Severe weather 3%

All flights IAD → SFO · Connecting off UA 1434? Check the risk

UA 1434: JAX → IAD

Scheduled to leave Jacksonville at 9:20 a.m. local time. Over the past year it arrived on time 88% of the time (212 flights), in line with other UA flights on the route at that hour (90%). Last seen in the data Aug 29, 2026.

Month by month

40%70%100%Dec 2025: 93% on time (27 flights)93DecJan 2026: too few flights (5 flights)JanFeb 2026: 88% on time (17 flights)88FebMar 2026: 87% on time (31 flights)87MarApr 2026: 97% on time (30 flights)97AprMay 2026: 92% on time (25 flights)92MayJun 2026: 90% on time (30 flights)90JunJul 2026: 77% on time (31 flights)77JulAug 2026: 81% on time (16 flights)81Aug

By day of week

DayFlightsOn time
Monday3181%
Tuesday2496%
Wednesday2793%
Thursday3197%
Friday3485%
Saturday3485%
Sunday3184%

Why it was late

Airline (crew, maintenance, ops) 91%Air traffic & airport (NAS) 9%

All flights JAX → IAD · Connecting off UA 1434? Check the risk

Questions

How often is UA 1434 from IAD to SFO late?

United Airlines 1434 from Washington, DC to San Francisco, CA arrived 15 or more minutes late, was diverted or was cancelled on 23% of 328 scheduled flights between September 2025 and August 2026. 0.3% were cancelled.

How often is UA 1434 from JAX to IAD late?

United Airlines 1434 from Jacksonville, FL to Washington, DC arrived 15 or more minutes late, was diverted or was cancelled on 12% of 212 scheduled flights between September 2025 and August 2026. 1.9% 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.