Great Falls International in May 2026

86.1%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 173 domestic departures from Great Falls International (GTF). 86.1% left less than 15 minutes late and 87.9% reached their destination on time; 1.2% were cancelled.

Nationally that month, 77.1% of flights departed on time and 77.6% arrived on time, so GTF departures were 9.0 points above the national departure figure.

A year earlier, in May 2025, the airport had 223 departures with 87.4% leaving on time: a change of −1.3 points, with flights down 22%.

Flights arriving at GTF that month were on time 82.7% of the time (173 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, air carrier 70%, late-arriving aircraft 11% and extreme weather 9%.

On time 87.9%
Arrived 15+ minutes late 11.0%
Cancelled 1.2%
Diverted 0.0%

Every scheduled departure from GTF 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	GTF, 12 months to Jul 2026	All reported flights, May 2026
Departed on time	86.1%	87.4%	88.2%	77.1%
Arrived on time	87.9%	85.2%	87.7%	77.6%
Cancelled	1.2%	0.0%	0.8%	0.9%
Average departure delay (late minutes only)	14.3 min	9.4 min	10.6 min	16.0 min
Scheduled departures a day	6	7	6	20,391
Scheduled departures	173	223	2,168	611,735

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
OO SkyWest Airlines	93	54%	90.3%	-1.7 min	0.0%
UA United Airlines	62	36%	83.9%	1.3 min	3.2%
G4 Allegiant Air	18	10%	88.9%	-1.6 min	0.0%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
GTF–SLC	Great Falls to Salt Lake City	93	90.3%	-1.7 min	0.0%
GTF–DEN	Great Falls to Denver	62	83.9%	1.3 min	3.2%
GTF–AZA	Great Falls to Phoenix	9	88.9%	3.9 min	0.0%
GTF–LAS	Great Falls to Las Vegas	9	88.9%	-7.1 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	70.3%	33.0%	1,568
Late-arriving aircraft	11.2%	40.4%	250
National Aviation System	9.2%	20.5%	206
Extreme weather	9.3%	6.0%	207
Security	0.0%	0.1%	0

2,231 delay minutes on 19 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 GTF on time in May 2026?

86.1% of 173 scheduled domestic departures left less than 15 minutes late, and 87.9% 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, 87.4% of 223 departures left on time and 0.0% were cancelled, against 86.1% and 1.2% 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 GTF · methodology · corrections.