Missoula Montana in May 2026

86.8%departed on time

BTS: A flight is counted as on time if it arrived less than 15 minutes after its scheduled time. Only carriers with at least 0.5 percent of domestic scheduled passenger revenue report.

In May 2026, reporting carriers scheduled 432 domestic departures from Missoula Montana (MSO). 86.8% left less than 15 minutes late and 87.7% reached their destination on time; 0.5% were cancelled.

Nationally that month, 77.1% of flights departed on time and 77.6% arrived on time, so MSO departures were 9.7 points above the national departure figure.

A year earlier, in May 2025, the airport had 324 departures with 78.1% leaving on time: a change of +8.7 points, with flights up 33%.

Flights arriving at MSO that month were on time 85.9% of the time (434 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, air carrier 65%, national aviation system 19% and late-arriving aircraft 13%.

On time 87.7%
Arrived 15+ minutes late 11.3%
Cancelled 0.5%
Diverted 0.5%

Every scheduled departure from MSO in May 2026, judged by arrival at the destination.

May 2026 against a year earlier, the airport's year and the nation

Measure	May 2026	May 2025	MSO, 12 months to Jul 2026	All reported flights, May 2026
Departed on time	86.8%	78.1%	83.4%	77.1%
Arrived on time	87.7%	78.7%	82.1%	77.6%
Cancelled	0.5%	0.6%	0.7%	0.9%
Average departure delay (late minutes only)	13.0 min	17.1 min	14.8 min	16.0 min
Scheduled departures a day	14	11	14	20,391
Scheduled departures	432	324	5,003	611,735

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
OO SkyWest Airlines	129	30%	82.9%	0.5 min	0.8%
DL Delta Air Lines	93	22%	94.6%	-4.2 min	0.0%
UA United Airlines	73	17%	84.9%	-2.6 min	1.4%
MQ Envoy Air	62	14%	95.2%	-14.1 min	0.0%
AS Alaska Airlines	42	10%	88.1%	-9.5 min	0.0%
G4 Allegiant Air	22	5%	72.7%	73.0 min	0.0%
AA American Airlines	11	3%	90.9%	1.9 min	0.0%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
MSO–DEN	Missoula to Denver	93	81.7%	0.5 min	0.0%
MSO–SLC	Missoula to Salt Lake City	93	92.5%	-11.1 min	0.0%
MSO–MSP	Missoula to Minneapolis	56	94.6%	2.8 min	0.0%
MSO–SEA	Missoula to Seattle	54	90.7%	-10.5 min	0.0%
MSO–DFW	Missoula to Dallas/Fort Worth	42	95.2%	-7.2 min	0.0%
MSO–ORD	Missoula to Chicago	42	90.5%	-16.7 min	2.4%
MSO–LAX	Missoula to Los Angeles	19	84.2%	21.9 min	0.0%
MSO–SFO	Missoula to San Francisco	11	45.5%	19.9 min	9.1%
MSO–LAS	Missoula to Las Vegas	10	70.0%	24.2 min	0.0%
MSO–AZA	Missoula to Phoenix	9	88.9%	-1.9 min	0.0%
MSO–SNA	Missoula to Santa Ana	3	33.3%	460.3 min	0.0%

By scheduled departure hour

100

On-time share:under 62%6270768288% and over

Share of departures that left less than 15 minutes late, by scheduled hour (local time), May 2026.

Delay causes

BTS cause category	Share of delay minutes	National, May 2026	Minutes
Air carrier	65.2%	33.0%	3,184
Late-arriving aircraft	12.8%	40.4%	624
National Aviation System	19.0%	20.5%	926
Extreme weather	3.0%	6.0%	148
Security	0.0%	0.1%	0

4,882 delay minutes on 49 flights that arrived 15 or more minutes late and carried a cause report. Carriers assign the categories; see what each category means.

Questions and answers

How many flights left MSO on time in May 2026?

86.8% of 432 scheduled domestic departures left less than 15 minutes late, and 87.7% reached their destination on time. The national figures that month were 77.1% and 77.6%.

How does that compare with a year earlier?

In May 2025, 78.1% of 324 departures left on time and 0.6% were cancelled, against 86.8% and 0.5% in May 2026.

Provenance

Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for May 2026; public domain. Domestic scheduled flights by reporting carriers, totals and averages only. The site's data runs through July 2026. Full record for MSO · methodology · corrections.