ON TIMEBOARD

UA 1239 on time

United Airlines 1239: Chicago to Rochester at 1:55 p.m. (past 12 months)

On time
68%
220 flights · likely 61–74%
Cancelled
1.4%
of scheduled flights
Typical arrival
−1 min
median vs schedule
When late
+79 min
average delay
Similar flights
60%
UA, same route & hour

About 1 in 3 UA 1239 flights from Chicago arrived 15+ minutes late, diverted or cancelled over the past year (32%); 1.4% were cancelled. The typical flight landed 1 minutes early.

UA 1239: ORD → ROC

Scheduled to leave Chicago at 1:55 p.m. local time. Over the past year it arrived on time 68% of the time (220 flights), better than other UA flights on the route at that hour (60%). Last seen in the data Aug 31, 2026.

Month by month

40%70%100%Jul 2025: 58% on time (31 flights)58JulAug 2025: 74% on time (31 flights)74AugSep 2025: 63% on time (30 flights)63SepOct 2025: 70% on time (30 flights)70OctNov 2025: 68% on time (28 flights)68NovDec 2025: 73% on time (15 flights)73DecJan 2026: too few flights (5 flights)JanApr 2026: too few flights (1 flights)AprMay 2026: 69% on time (29 flights)69MayJun 2026: 69% on time (26 flights)69JunJul 2026: 67% on time (27 flights)67JulAug 2026: 66% on time (29 flights)66Aug

By day of week

DayFlightsOn time
Monday3566%
Tuesday3275%
Wednesday3263%
Thursday3379%
Friday3376%
Saturday2162%
Sunday3453%

Why it was late

Late inbound plane 49%Airline (crew, maintenance, ops) 32%Air traffic & airport (NAS) 15%Severe weather 5%

All flights ORD → ROC · Connecting off UA 1239? Check the risk

Questions

How often is UA 1239 from ORD to ROC late?

United Airlines 1239 from Chicago, IL to Rochester, NY arrived 15 or more minutes late, was diverted or was cancelled on 32% of 220 scheduled flights between September 2025 and August 2026. 1.4% 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.