ON TIMEBOARD

UA 2356 on time

United Airlines 2356: Las Vegas to San Francisco at 7:45 a.m.; San Francisco to Boston at 10:05 a.m. (past 12 months). Figures below the title are for LAS → SFO, its busiest leg

On time
59%
346 flights · likely 54–64%
Cancelled
0.3%
of scheduled flights
Typical arrival
+6 min
median vs schedule
When late
+51 min
average delay
Similar flights
57%
UA, same route & hour

About 1 in 2 UA 2356 flights from Las Vegas arrived 15+ minutes late, diverted or cancelled over the past year (41%); 0.3% were cancelled. The typical flight landed 6 minutes late.

UA 2356: LAS → SFO

Scheduled to leave Las Vegas at 7:45 a.m. local time. Over the past year it arrived on time 59% of the time (346 flights), in line with other UA flights on the route at that hour (57%). Last seen in the data Aug 31, 2026.

Month by month

30%65%100%Sep 2025: 53% on time (30 flights)53SepOct 2025: 55% on time (31 flights)55OctNov 2025: 50% on time (30 flights)50NovDec 2025: 67% on time (15 flights)67DecJan 2026: 84% on time (31 flights)84JanFeb 2026: 71% on time (28 flights)71FebMar 2026: 84% on time (31 flights)84MarApr 2026: 77% on time (30 flights)77AprMay 2026: 35% on time (31 flights)35MayJun 2026: 53% on time (30 flights)53JunJul 2026: 42% on time (31 flights)42JulAug 2026: 39% on time (28 flights)39Aug

By day of week

DayFlightsOn time
Monday5159%
Tuesday4657%
Wednesday4943%
Thursday5052%
Friday5064%
Saturday5072%
Sunday5066%

Why it was late

Air traffic & airport (NAS) 74%Late inbound plane 13%Airline (crew, maintenance, ops) 12%Severe weather 1%

All flights LAS → SFO · Connecting off UA 2356? Check the risk

UA 2356: SFO → BOS

Scheduled to leave San Francisco at 10:05 a.m. local time. Over the past year it arrived on time 62% of the time (328 flights), worse than other UA flights on the route at that hour (67%). Last seen in the data Aug 31, 2026.

Month by month

20%60%100%Sep 2025: 27% on time (30 flights)27SepOct 2025: 45% on time (31 flights)45OctNov 2025: 73% on time (30 flights)73NovDec 2025: 81% on time (31 flights)81DecJan 2026: too few flights (5 flights)JanFeb 2026: 76% on time (17 flights)76FebMar 2026: 61% on time (31 flights)61MarApr 2026: 60% on time (30 flights)60AprMay 2026: 55% on time (31 flights)55MayJun 2026: 73% on time (30 flights)73JunJul 2026: 71% on time (31 flights)71JulAug 2026: 68% on time (31 flights)68Aug

By day of week

DayFlightsOn time
Monday4858%
Tuesday4661%
Wednesday4659%
Thursday4764%
Friday4757%
Saturday4777%
Sunday4760%

Why it was late

Air traffic & airport (NAS) 60%Late inbound plane 19%Airline (crew, maintenance, ops) 18%Severe weather 2%

All flights SFO → BOS · Connecting off UA 2356? Check the risk

Questions

How often is UA 2356 from LAS to SFO late?

United Airlines 2356 from Las Vegas, NV to San Francisco, CA arrived 15 or more minutes late, was diverted or was cancelled on 41% of 346 scheduled flights between September 2025 and August 2026. 0.3% were cancelled.

How often is UA 2356 from SFO to BOS late?

United Airlines 2356 from San Francisco, CA to Boston, MA arrived 15 or more minutes late, was diverted or was cancelled on 38% of 328 scheduled flights between September 2025 and August 2026. 0.9% 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.