ON TIMEBOARD

UA 2040 on time

United Airlines 2040: Boston to Chicago at 4:25 p.m. (past 12 months)

On time
52%
360 flights · likely 47–57%
Cancelled
2.2%
of scheduled flights
Typical arrival
+11 min
median vs schedule
When late
+72 min
average delay
Similar flights
52%
UA, same route & hour

About 1 in 2 UA 2040 flights from Boston arrived 15+ minutes late, diverted or cancelled over the past year (48%); 2.2% were cancelled. The typical flight landed 11 minutes late.

UA 2040: BOS → ORD

Scheduled to leave Boston at 4:25 p.m. local time. Over the past year it arrived on time 52% of the time (360 flights), in line with other UA flights on the route at that hour (52%). Last seen in the data Aug 31, 2026.

Month by month

30%65%100%Sep 2025: 40% on time (30 flights)40SepOct 2025: 42% on time (31 flights)42OctNov 2025: 59% on time (29 flights)59NovDec 2025: 53% on time (30 flights)53DecJan 2026: 40% on time (30 flights)40JanFeb 2026: 61% on time (28 flights)61FebMar 2026: 48% on time (31 flights)48MarApr 2026: 57% on time (30 flights)57AprMay 2026: 77% on time (31 flights)77MayJun 2026: 50% on time (30 flights)50JunJul 2026: 47% on time (30 flights)47JulAug 2026: 50% on time (30 flights)50Aug

By day of week

DayFlightsOn time
Monday5349%
Tuesday5169%
Wednesday5248%
Thursday5157%
Friday5238%
Saturday4955%
Sunday5248%

Why it was late

Air traffic & airport (NAS) 56%Late inbound plane 21%Airline (crew, maintenance, ops) 20%Severe weather 3%

All flights BOS → ORD · Connecting off UA 2040? Check the risk

Questions

How often is UA 2040 from BOS to ORD late?

United Airlines 2040 from Boston, MA to Chicago, IL arrived 15 or more minutes late, was diverted or was cancelled on 48% of 360 scheduled flights between September 2025 and August 2026. 2.2% 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.