Boise Air Terminal in May 2026

80.3%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 2,040 domestic departures from Boise Air Terminal (BOI). 80.3% left less than 15 minutes late and 80.1% reached their destination on time; 0.2% were cancelled.

Nationally that month, 77.1% of flights departed on time and 77.6% arrived on time, so BOI departures were 3.2 points above the national departure figure.

A year earlier, in May 2025, the airport had 1,993 departures with 87.1% leaving on time: a change of −6.8 points, with flights up 2%.

Flights arriving at BOI that month were on time 78.6% of the time (2,037 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 35%, air carrier 33% and national aviation system 26%.

On time 80.1%
Arrived 15+ minutes late 19.3%
Cancelled 0.2%
Diverted 0.3%

Every scheduled departure from BOI 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	BOI, 12 months to Jul 2026	All reported flights, May 2026
Departed on time	80.3%	87.1%	83.9%	77.1%
Arrived on time	80.1%	85.7%	82.9%	77.6%
Cancelled	0.2%	0.2%	0.5%	0.9%
Average departure delay (late minutes only)	14.4 min	8.9 min	12.2 min	16.0 min
Scheduled departures a day	68	66	65	20,391
Scheduled departures	2,040	1,993	23,701	611,735

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
OO SkyWest Airlines	919	45%	80.7%	3.2 min	0.1%
WN Southwest Airlines	415	20%	74.5%	9.7 min	0.0%
DL Delta Air Lines	234	11%	88.5%	-4.0 min	0.0%
AS Alaska Airlines	193	9%	87.6%	-4.4 min	0.0%
UA United Airlines	124	6%	76.6%	13.4 min	0.8%
AA American Airlines	104	5%	69.2%	31.5 min	2.9%
MQ Envoy Air	31	2%	83.9%	2.4 min	0.0%
G4 Allegiant Air	11	1%	72.7%	20.0 min	0.0%
F9 Frontier Airlines	9	0%	77.8%	-3.3 min	0.0%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
BOI–SEA	Boise to Seattle	366	84.7%	-3.0 min	0.0%
BOI–DEN	Boise to Denver	261	78.9%	5.6 min	0.4%
BOI–PHX	Boise to Phoenix	156	83.3%	9.2 min	0.0%
BOI–SLC	Boise to Salt Lake City	155	96.1%	-8.5 min	0.0%
BOI–SFO	Boise to San Francisco	146	44.5%	33.8 min	0.0%
BOI–LAX	Boise to Los Angeles	138	94.9%	-8.8 min	0.0%
BOI–LAS	Boise to Las Vegas	123	74.0%	9.8 min	0.0%
BOI–SAN	Boise to San Diego	101	82.2%	3.1 min	0.0%
BOI–ORD	Boise to Chicago	93	78.5%	6.8 min	0.0%
BOI–PDX	Boise to Portland	76	85.5%	-4.9 min	1.3%
BOI–DFW	Boise to Dallas/Fort Worth	73	65.8%	44.5 min	4.1%
BOI–SMF	Boise to Sacramento	67	74.6%	4.6 min	0.0%

By scheduled departure hour

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	32.7%	33.0%	8,820
Late-arriving aircraft	35.3%	40.4%	9,535
National Aviation System	26.3%	20.5%	7,094
Extreme weather	5.8%	6.0%	1,563
Security	0.0%	0.1%	0

27,012 delay minutes on 393 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 BOI on time in May 2026?

80.3% of 2,040 scheduled domestic departures left less than 15 minutes late, and 80.1% 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, 87.1% of 1,993 departures left on time and 0.2% were cancelled, against 80.3% and 0.2% 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 BOI · methodology · corrections.