ON TIMEBOARD
PDX Portland / MSO Missoula

PDX → MSO on time

Portland (Portland, OR) to Missoula Montana (Missoula, MT). Every scheduled flight, September 2025 to August 2026.

On time
87%
arrived < 15 min late
Cancelled
0.4%
484 flights
Typical arrival
−4 min
median vs schedule
When late
+42 min
average delay
Flights / day
1
1 airline

87% of flights from Portland to Missoula arrived on time over the past 12 months. That is better than the typical U.S. route. The 10 a.m. departures ran on time 92% of the time; the 9 p.m. ones 83%. 3% 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 PDX → MSO: when a flight was late, it was under 45 minutes late 73% of the time. About 1 in 48 flights landed an hour or more late, and 1 in 484 three hours or more; 0.4% were cancelled outright.

Share of all 484 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
Alaska Airlines48487%0.4%−4 min2.1%+42 minHorizon Air 74%, SkyWest 26%

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 PDX). Delays build through the day as late planes knock on, so early flights usually do best.

40%70%100%10 a.m. departures: 92% on time (203 flights)9210a11 a.m. departures: 90% on time (101 flights)9011anoon departures: too few flights12p1 p.m. departures: too few flights1p2 p.m. departures: too few flights (70 flights)2p3 p.m. departures: too few flights3p4 p.m. departures: too few flights4p5 p.m. departures: too few flights5p6 p.m. departures: too few flights6p7 p.m. departures: too few flights7p8 p.m. departures: too few flights8p9 p.m. departures: 83% on time (110 flights)839p
PDX → MSO, 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

Last flight of the day

On PDX → MSO, each airline's last flight of the day was cancelled 0.8% of the time, against 0.0% for its earlier flights, about the same. It arrived 3+ hours late 0.0% of the time (earlier flights: 0.0%). 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
Alaska Airlines2:30 p.m.0.8%0.0%0.0%first flight 2:30 p.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.

By month

Each calendar month pooled over 2023–2026. Best: May (90%). Worst: July (81%).

40%70%100%Jan: too few flights (69 flights)JanFeb: too few flights (61 flights)FebMar: too few flights (79 flights)MarApr: too few flights (90 flights)AprMay: 90% on time (110 flights)90MayJun: 84% on time (120 flights)84JunJul: 81% on time (139 flights)81JulAug: 89% on time (118 flights)89AugSep: too few flights (67 flights)SepOct: too few flights (84 flights)OctNov: too few flights (85 flights)NovDec: too few flights (88 flights)Dec

By day of week

DayFlightsOn timeCancelled
Monday74——
Tuesday69——
Wednesday72——
Thursday71——
Friday67——
Saturday62——
Sunday69——

Why flights were late

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

Late inbound plane 50%Airline (crew, maintenance, ops) 39%Severe weather 6%Air traffic & airport (NAS) 5%

Cancellations: airline 1 · weather 1

Month by month

Not enough months with data to draw a trend.

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
AS 214610:30 a.m.17192%0.6%−9 minHorizon Air

Questions

How often are flights from PDX to MSO on time?

87% of 484 scheduled flights from Portland, OR to Missoula, MT arrived within 15 minutes of schedule between September 2025 and August 2026. 0.4% were cancelled.

What is the best time of day to fly PDX to MSO?

Flights scheduled to leave at 10 a.m. were the most reliable (92% on time). The 9 p.m. departures were the least (83%).

What month has the most delays from PDX to MSO?

July (81% on time). The best month is May (90%), over 2023–2026.

Is the last flight of the day from PDX to MSO more likely to be cancelled?

Yes. Each airline's last PDX–MSO flight of the day was cancelled 0.8% of the time over the past year, against 0.0% 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.