Boise Air Terminal in April 2025

87.8%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 April 2025, reporting carriers scheduled 1,927 domestic departures from Boise Air Terminal (BOI). 87.8% left less than 15 minutes late and 85.2% reached their destination on time; 0.0% were cancelled.

Nationally that month, 80.6% of flights departed on time and 79.5% arrived on time, so BOI departures were 7.2 points above the national departure figure.

A year earlier, in April 2024, the airport had 1,787 departures with 86.8% leaving on time: a change of +1.0 points, with flights up 8%.

Flights arriving at BOI that month were on time 82.9% of the time (1,927 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 42%, air carrier 32% and national aviation system 23%.

On time 85.2%
Arrived 15+ minutes late 14.6%
Cancelled 0.0%
Diverted 0.2%

Every scheduled departure from BOI in April 2025, judged by arrival at the destination.

April 2025 against a year earlier, the airport's year and the nation

Measure	Apr 2025	Apr 2024	BOI, 12 months to Jul 2026	All reported flights, Apr 2025
Departed on time	87.8%	86.8%	83.9%	80.6%
Arrived on time	85.2%	85.2%	82.9%	79.5%
Cancelled	0.0%	0.0%	0.5%	0.8%
Average departure delay (late minutes only)	9.0 min	9.0 min	12.2 min	14.1 min
Scheduled departures a day	64	60	65	19,465
Scheduled departures	1,927	1,787	23,701	583,950

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
OO SkyWest Airlines	969	50%	88.2%	-3.8 min	0.0%
WN Southwest Airlines	447	23%	85.5%	-1.0 min	0.0%
DL Delta Air Lines	238	12%	87.4%	0.0 min	0.0%
UA United Airlines	120	6%	75.0%	3.9 min	0.0%
AA American Airlines	60	3%	66.7%	18.4 min	0.0%
AS Alaska Airlines	60	3%	73.3%	8.7 min	0.0%
G4 Allegiant Air	20	1%	65.0%	23.9 min	0.0%
NK Spirit Airlines	13	1%	76.9%	5.9 min	0.0%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
BOI–SEA	Boise to Seattle	344	85.5%	-4.0 min	0.0%
BOI–DEN	Boise to Denver	242	79.3%	4.1 min	0.0%
BOI–PHX	Boise to Phoenix	207	83.6%	7.3 min	0.0%
BOI–SLC	Boise to Salt Lake City	136	91.2%	-4.2 min	0.0%
BOI–SFO	Boise to San Francisco	129	77.5%	-2.0 min	0.0%
BOI–LAS	Boise to Las Vegas	114	80.7%	2.2 min	0.0%
BOI–LAX	Boise to Los Angeles	111	95.5%	-14.8 min	0.0%
BOI–SMF	Boise to Sacramento	84	94.0%	-6.6 min	0.0%
BOI–PDX	Boise to Portland	81	95.1%	-3.9 min	0.0%
BOI–SAN	Boise to San Diego	69	85.5%	0.4 min	0.0%
BOI–DFW	Boise to Dallas/Fort Worth	60	66.7%	18.4 min	0.0%
BOI–MSP	Boise to Minneapolis	60	91.7%	-7.0 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), April 2025.

Delay causes

BTS cause category	Share of delay minutes	National, Apr 2025	Minutes
Air carrier	31.7%	32.7%	5,401
Late-arriving aircraft	41.6%	39.4%	7,102
National Aviation System	22.5%	22.2%	3,838
Extreme weather	4.2%	5.5%	721
Security	0.0%	0.2%	0

17,062 delay minutes on 281 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 April 2025?

87.8% of 1,927 scheduled domestic departures left less than 15 minutes late, and 85.2% reached their destination on time. The national figures that month were 80.6% and 79.5%.

How does that compare with a year earlier?

In April 2024, 86.8% of 1,787 departures left on time and 0.0% were cancelled, against 87.8% and 0.0% in April 2025.

Provenance

Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance, file for April 2025; 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.