Charles M. Schulz - Sonoma County in April 2025

80.2%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 363 domestic departures from Charles M. Schulz - Sonoma County (STS). 80.2% left less than 15 minutes late and 76.3% reached their destination on time; 0.3% were cancelled.

Nationally that month, 80.6% of flights departed on time and 79.5% arrived on time, so STS departures were level with the national departure figure.

A year earlier, in April 2024, the airport had 265 departures with 85.7% leaving on time: a change of −5.5 points, with flights up 37%.

Flights arriving at STS that month were on time 80.2% of the time (363 scheduled arrivals).

Of the delay minutes that carriers assigned to a BTS cause category that month, late-arriving aircraft 43%, air carrier 32% and national aviation system 15%.

On time 76.3%
Arrived 15+ minutes late 23.1%
Cancelled 0.3%
Diverted 0.3%

Every scheduled departure from STS 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	STS, 12 months to Jul 2026	All reported flights, Apr 2025
Departed on time	80.2%	85.7%	80.4%	80.6%
Arrived on time	76.3%	80.0%	78.8%	79.5%
Cancelled	0.3%	0.0%	1.7%	0.8%
Average departure delay (late minutes only)	11.9 min	9.1 min	13.2 min	14.1 min
Scheduled departures a day	12	9	16	19,465
Scheduled departures	363	265	5,714	583,950

Airlines that month

Reporting carrier	Flights	Share	On time	Avg arrival delay	Cancelled
OO SkyWest Airlines	299	82%	76.6%	8.0 min	0.3%
AA American Airlines	30	8%	73.3%	14.7 min	0.0%
MQ Envoy Air	30	8%	83.3%	-0.4 min	0.0%
AS Alaska Airlines	4	1%	25.0%	62.5 min	0.0%

Busiest routes that month

Route	Cities	Flights	On time	Avg arrival delay	Cancelled
STS–LAX	Santa Rosa to Los Angeles	72	81.9%	5.3 min	0.0%
STS–PHX	Santa Rosa to Phoenix	60	78.3%	7.2 min	0.0%
STS–SAN	Santa Rosa to San Diego	60	68.3%	10.3 min	1.7%
STS–SNA	Santa Rosa to Santa Ana	60	70.0%	7.1 min	0.0%
STS–PDX	Santa Rosa to Portland	38	81.6%	7.8 min	0.0%
STS–BUR	Santa Rosa to Burbank	30	80.0%	12.4 min	0.0%
STS–LAS	Santa Rosa to Las Vegas	30	86.7%	7.6 min	0.0%
STS–SEA	Santa Rosa to Seattle	13	53.8%	25.7 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), April 2025.

Delay causes

BTS cause category	Share of delay minutes	National, Apr 2025	Minutes
Air carrier	31.7%	32.7%	1,392
Late-arriving aircraft	42.5%	39.4%	1,867
National Aviation System	15.0%	22.2%	660
Extreme weather	10.8%	5.5%	474
Security	0.0%	0.2%	0

4,393 delay minutes on 84 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 STS on time in April 2025?

80.2% of 363 scheduled domestic departures left less than 15 minutes late, and 76.3% 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, 85.7% of 265 departures left on time and 0.0% were cancelled, against 80.2% and 0.3% 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 STS · methodology · corrections.