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Route on-time record

ORD to MSO: most on-time flights and the best time to fly

Chicago (Chicago O'Hare International Airport) to Missoula (Missoula Montana Airport). 546 nonstop flights in Jun 2025 to May 2026, 77% arrived within 15 minutes and 0.4% were cancelled. The most reliable flight number was United 1180 at 8:40 AM.

Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.

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ORD → MSO

Chicago to Missoula: 546 nonstop flights a year

On time (12 months)

77%

Cancelled

0.4%

avg delay 14 min

Best time to leave

Before 9 AM

87% on time vs 66% 6 to 9 PM

Most reliable airline

United

84% chance on time

Check ORD to MSO fares

Fares open on our travel partner (Aviasales). Pick the flight number you chose here.

Most reliable nonstop flights

Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.

  1. #1 · United 1180

    8:40 AM → 11:32 AM3h 52m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    90%

    chance on time

    On time (history)
    100%
    Cancelled
    0.0%
    Avg arrival delay
    0 min
    • Arrived on time 100% of the time (11 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 87% on time; 6 to 9 PM: 66%).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 43% of its 237 ground stops and delay programs started).

    Limited track record · 11 flights

    Find United 1180 fares Opens this date on Aviasales

  2. #2 · Envoy 3718 · sold as American Eagle

    9:55 AM → 12:49 PM3h 54m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    79%

    chance on time

    On time (history)
    100%
    Cancelled
    0.0%
    Avg arrival delay
    1 min
    • Arrived on time 100% of the time (11 flights, Jun 2025 to May 2026).
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 43% of its 237 ground stops and delay programs started).

    Limited track record · 11 flights

    Find 9:55 AM flight fares Opens this date on Aviasales

  3. #3 · Envoy 4199 · sold as American Eagle

    9:40 AM → 12:38 PM3h 58m nonstop

    Local times, typical schedule. Last flown 2026-05-20.

    69%

    chance on time

    On time (history)
    66%
    Cancelled
    0.0%
    Avg arrival delay
    17 min
    • Arrived on time 66% of the time (152 flights, Jun 2025 to May 2026).
    • Never cancelled in 154 scheduled flights.
    • Departs outside ORD's trouble window (2 PM to 8 PM, when 43% of its 237 ground stops and delay programs started).

    Moderate track record · 152 flights

    Find 9:40 AM flight fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

  • United Airlines84%

    104 flights · 88% on time as flown · 0.2% cancel

  • Envoy Air (sold as American Eagle)73%

    394 flights · 73% on time as flown · 0.3% cancel

On time by departure time

All airlines, scheduled local departure, Jun 2025 to May 2026.

  • Before 9 AM87%

    127 flights · avg delay 9 min

  • 9 AM to noon77%

    304 flights · avg delay 11 min

  • 6 to 9 PM66%

    108 flights · avg delay 26 min

Best day: Tuesday (87%). Worst: Sunday (74%).

On time by month

All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.

J
71
F
-
M
60
A
80
M
93
J
85
J
75
A
76
S
88
O
88
N
-
D
-

What delays this route

  • Air traffic control and airport volume28%
  • Late-arriving aircraft27%
  • Airline (crew, maintenance, boarding)26%
  • Severe weather19%

Share of delay minutes by the cause airlines report to the US DOT.

Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure

Finding the most reliable connections from ORD to MSO…

ORD to MSO questions

What time of day is best to fly ORD to MSO?
Before 9 AM: 87% of flights arrived on time, against 66% for departures 6 to 9 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
Which airline is most on time from ORD to MSO?
United, with a season-adjusted 84% chance of operating and arriving on time over 104 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
What is the worst month for delays on ORD to MSO?
March (60% on time); the best was May (93%), averaged over Jun 2023 to May 2026.
Is this a prediction for my flight?
No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.

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Live status: FAA delays and ground stops