ON TIMEBOARD

UA 4631 on time

United Airlines 4631: Casper to Denver at 9:00 a.m. (past 12 months)

On time
84%
309 flights · likely 79–87%
Cancelled
0.0%
of scheduled flights
Typical arrival
−5 min
median vs schedule
When late
+97 min
average delay
Similar flights
83%
UA, same route & hour

About 1 in 6 UA 4631 flights from Casper arrived 15+ minutes late, diverted or cancelled over the past year (17%); 0.0% were cancelled. The typical flight landed 5 minutes early.

UA 4631: CPR → DEN

Scheduled to leave Casper at 9:00 a.m. local time, operated by SkyWest as OO 4631. Over the past year it arrived on time 84% of the time (309 flights), in line with other UA flights on the route at that hour (83%). Last seen in the data Aug 31, 2026.

Month by month

40%70%100%Oct 2025: too few flights (6 flights)OctNov 2025: 93% on time (30 flights)93NovDec 2025: 74% on time (31 flights)74DecJan 2026: 74% on time (31 flights)74JanFeb 2026: 81% on time (27 flights)81FebMar 2026: 77% on time (31 flights)77MarApr 2026: 80% on time (30 flights)80AprMay 2026: 81% on time (31 flights)81MayJun 2026: 87% on time (30 flights)87JunJul 2026: 94% on time (31 flights)94JulAug 2026: 94% on time (31 flights)94Aug

By day of week

DayFlightsOn time
Monday4580%
Tuesday4480%
Wednesday4484%
Thursday4384%
Friday4480%
Saturday4486%
Sunday4591%

Why it was late

Airline (crew, maintenance, ops) 61%Air traffic & airport (NAS) 20%Late inbound plane 11%Severe weather 8%

All flights CPR → DEN · Connecting off UA 4631? Check the risk

Questions

How often is UA 4631 from CPR to DEN late?

United Airlines 4631 from Casper, WY to Denver, CO arrived 15 or more minutes late, was diverted or was cancelled on 17% of 309 scheduled flights between September 2025 and August 2026. 0.0% 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.