ON TIMEBOARD

UA 1505 on time

United Airlines 1505: Seattle to Denver at 8:40 a.m.; Denver to Newark at 1:41 p.m. (past 12 months). Figures below the title are for SEA → DEN, its busiest leg

On time
90%
363 flights · likely 87–93%
Cancelled
0.8%
of scheduled flights
Typical arrival
−12 min
median vs schedule
When late
+132 min
average delay
Similar flights
90%
UA, same route & hour

About 1 in 10 UA 1505 flights from Seattle arrived 15+ minutes late, diverted or cancelled over the past year (10%); 0.8% were cancelled. The typical flight landed 12 minutes early.

UA 1505: SEA → DEN

Scheduled to leave Seattle at 8:40 a.m. local time. Over the past year it arrived on time 90% of the time (363 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%Sep 2025: 97% on time (30 flights)97SepOct 2025: 97% on time (31 flights)97OctNov 2025: 93% on time (28 flights)93NovDec 2025: 90% on time (31 flights)90DecJan 2026: 90% on time (31 flights)90JanFeb 2026: 82% on time (28 flights)82FebMar 2026: 77% on time (31 flights)77MarApr 2026: 97% on time (30 flights)97AprMay 2026: 90% on time (31 flights)90MayJun 2026: 90% on time (30 flights)90JunJul 2026: 94% on time (31 flights)94JulAug 2026: 87% on time (31 flights)87Aug

By day of week

DayFlightsOn time
Monday5392%
Tuesday5288%
Wednesday5292%
Thursday5196%
Friday5188%
Saturday5290%
Sunday5285%

Why it was late

Airline (crew, maintenance, ops) 47%Late inbound plane 29%Air traffic & airport (NAS) 13%Severe weather 11%

All flights SEA → DEN · Connecting off UA 1505? Check the risk

UA 1505: DEN → EWR

Scheduled to leave Denver at 1:41 p.m. local time. Over the past year it arrived on time 67% of the time (320 flights), in line with other UA flights on the route at that hour (66%). Last seen in the data Aug 31, 2026.

Month by month

30%65%100%Sep 2025: too few flights (6 flights)SepOct 2025: 61% on time (31 flights)61OctNov 2025: 67% on time (30 flights)67NovDec 2025: 68% on time (31 flights)68DecJan 2026: 81% on time (31 flights)81JanFeb 2026: 71% on time (28 flights)71FebMar 2026: 71% on time (31 flights)71MarApr 2026: 76% on time (29 flights)76AprMay 2026: too few flights (11 flights)MayJun 2026: 67% on time (30 flights)67JunJul 2026: 39% on time (31 flights)39JulAug 2026: 61% on time (31 flights)61Aug

By day of week

DayFlightsOn time
Monday4672%
Tuesday4571%
Wednesday4569%
Thursday4661%
Friday4665%
Saturday4672%
Sunday4659%

Why it was late

Air traffic & airport (NAS) 54%Late inbound plane 27%Airline (crew, maintenance, ops) 18%Severe weather 1%

All flights DEN → EWR · Connecting off UA 1505? Check the risk

Questions

How often is UA 1505 from SEA to DEN late?

United Airlines 1505 from Seattle, WA to Denver, CO arrived 15 or more minutes late, was diverted or was cancelled on 10% of 363 scheduled flights between September 2025 and August 2026. 0.8% were cancelled.

How often is UA 1505 from DEN to EWR late?

United Airlines 1505 from Denver, CO to Newark, NJ arrived 15 or more minutes late, was diverted or was cancelled on 33% of 320 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.