ON TIMEBOARD

ORD → BZN on time

Chicago O'Hare (Chicago, IL) to Bozeman Yellowstone (Bozeman, MT). Every scheduled flight, September 2025 to August 2026.

On time
67%
arrived < 15 min late
Cancelled
0.6%
1,252 flights
Typical arrival
+2 min
median vs schedule
When late
+66 min
average delay
Flights / day
3
2 airlines

67% of flights from Chicago to Bozeman arrived on time over the past 12 months. That is worse than the typical U.S. route. The 9 a.m. departures ran on time 77% of the time; the 7 p.m. ones 49%. Most reliable airline: United Airlines (71%). 13% of flights arrived more than an hour late or not at all.

How late?

The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for ORD → BZN: when a flight was late, it was under 45 minutes late 52% of the time. About 1 in 9 flights landed an hour or more late, and 1 in 54 three hours or more; 0.6% were cancelled outright.

Share of all 1,252 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
United Airlines76671%0.5%+1 min9.7%+70 minUnited Airlines 94%, SkyWest 6%
American Airlines48662%0.6%+4 min14.4%+61 minAmerican Airlines 92%, Envoy 8%

Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.

Best time of day to fly

On-time rate by scheduled departure hour (local time at ORD). Delays build through the day as late planes knock on, so early flights usually do best.

40%70%100%8 a.m. departures: too few flights (30 flights)8a9 a.m. departures: 77% on time (388 flights)779a10 a.m. departures: 66% on time (238 flights)6610a11 a.m. departures: too few flights (30 flights)11anoon departures: 77% on time (101 flights)7712p1 p.m. departures: 57% on time (121 flights)571p2 p.m. departures: too few flights2p3 p.m. departures: too few flights (10 flights)3p4 p.m. departures: too few flights (99 flights)4p5 p.m. departures: too few flights (1 flights)5p6 p.m. departures: too few flights (1 flights)6p7 p.m. departures: 49% on time (101 flights)497p8 p.m. departures: 54% on time (115 flights)548p
ORD → BZN, share of flights arriving on time, by departure hour. Hours with under 100 flights are greyed out.
82%+ on time76–82%68–76%under 68%too few flights

By airline and hour

DepartsUnited AirlinesAmerican Airlines
9 a.m.79%—
10 a.m.—66%
noon77%—
1 p.m.—57%
8 p.m.57%—

Last flight of the day

On ORD → BZN, each airline's last flight of the day was cancelled 1.1% of the time, against 0.2% for its earlier flights (6.6× as often). It arrived 3+ hours late 3.4% of the time (earlier flights: 0.8%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.

AirlineLast departureLast: cancelledLast: 3h+ lateEarlier: cancelledNext morning
American Airlines1:29 p.m.0.9%0.9%0.0%first flight 10:09 a.m.
United Airlines8:15 p.m.1.1%5.3%0.3%first flight 9:10 a.m.

Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.

If you need to be in BZN tonight, book an earlier flight so there's a backup if it's cancelled.

By month

Each calendar month pooled over 2023–2026. Best: September (85%). Worst: January (63%).

40%70%100%Jan: 63% on time (258 flights)63JanFeb: 77% on time (230 flights)77FebMar: 67% on time (282 flights)67MarApr: 80% on time (123 flights)80AprMay: 80% on time (225 flights)80MayJun: 73% on time (362 flights)73JunJul: 64% on time (379 flights)64JulAug: 65% on time (360 flights)65AugSep: 85% on time (308 flights)85SepOct: 75% on time (262 flights)75OctNov: too few flights (73 flights)NovDec: 71% on time (223 flights)71Dec

By day of week

DayFlightsOn timeCancelled
Monday18870%1.1%
Tuesday16176%0.6%
Wednesday15971%0.0%
Thursday18468%0.5%
Friday19059%1.1%
Saturday18665%0.0%
Sunday18464%0.5%

Why flights were late

Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.

Late inbound plane 45%Air traffic & airport (NAS) 26%Airline (crew, maintenance, ops) 22%Severe weather 6%

Cancellations: weather 7

Month by month

40%70%100%Sep 2023Jan 2024Jan 2025Jan 2026Jun 2025: 76% on time, 0.0% cancelledJul 2025: 56% on time, 1.4% cancelledAug 2025: 69% on time, 2.8% cancelledSep 2025: 80% on time, 0.0% cancelledOct 2025: 68% on time, 0.0% cancelledJan 2026: 57% on time, 1.0% cancelledMar 2026: 50% on time, 0.9% cancelledJun 2026: 73% on time, 0.0% cancelledJul 2026: 69% on time, 1.9% cancelledAug 2026: 63% on time, 0.8% cancelled
Share of flights on time, by month (hover a point for cancellations)
ORD → BZN, monthly on-time and cancellation rate.

Flight numbers on this route

Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.

FlightDepartsFlightsOn timeCancelledTypical arrivalOperated by
UA 2249:10 a.m.28581%0.4%−3 minUnited Airlines
UA 5338:15 p.m.12654%2.4%+12 minUnited Airlines

Worst days in the past year

DateFlightsOn timeCancelled
Sep 13, 202550%0
Mar 13, 202640%0
Mar 16, 202640%0
Mar 15, 202640%1
Mar 6, 202640%0

Questions

How often are flights from ORD to BZN on time?

67% of 1,252 scheduled flights from Chicago, IL to Bozeman, MT arrived within 15 minutes of schedule between September 2025 and August 2026. 0.6% were cancelled.

What is the best time of day to fly ORD to BZN?

Flights scheduled to leave at 9 a.m. were the most reliable (77% on time). The 7 p.m. departures were the least (49%).

Which airline is most on time from ORD to BZN?

United Airlines: 71% of its 766 flights on the route arrived on time. American Airlines: 62%.

What month has the most delays from ORD to BZN?

January (63% on time). The best month is September (85%), over 2023–2026.

Is the last flight of the day from ORD to BZN more likely to be cancelled?

Yes. Each airline's last ORD–BZN flight of the day was cancelled 1.1% of the time over the past year, against 0.2% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.

Related

Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.