FlightRecord

Charles M. Schulz Sonoma County Airport (STS): Delays & On-Time Performance

Data through July 2026

Charles M. Schulz Sonoma County Airport (STS) is a tale of two seasons: departures ran 88% on-time in March 2026 but sank to 65% in December 2025. Across the year it averages 81% against a national 78%, over roughly 16 departures a day to 12 destinations.

Departures on-time
81%
left <15 min late
Avg dep delay
14 min
Arrivals on-time
79%
Cancelled
1.3%
Destinations
12
nonstop
Airlines
5

Plan your departure from STS

The choices most likely to improve your odds, based on this airport’s historical record.

Best departure time
Around 6 a.m.
94% on-time
Best day to fly
Saturday
83% on-time
Most reliable airline here
Envoy Air
82% on-time from STS
Cancellation risk
1.3%
below the US average
Check routes from STS ↓Compare nearby airports ↓

Monthly on-time trend

Monthly departure on-time percentage at STS50%75%100%August 2024: 83% on-time (338 flights)83Aug 2024September 2024: 83% on-time (345 flights)83October 2024: 81% on-time (348 flights)81November 2024: 74% on-time (396 flights)74Nov 2024December 2024: 76% on-time (387 flights)76January 2025: 84% on-time (279 flights)84February 2025: 79% on-time (250 flights)79Feb 2025March 2025: 82% on-time (319 flights)82April 2025: 80% on-time (363 flights)80May 2025: 79% on-time (455 flights)79May 2025June 2025: 73% on-time (404 flights)73July 2025: 72% on-time (385 flights)72August 2025: 80% on-time (435 flights)80Aug 2025September 2025: 82% on-time (484 flights)82October 2025: 85% on-time (404 flights)85November 2025: 81% on-time (484 flights)81Nov 2025December 2025: 65% on-time (406 flights)65January 2026: 85% on-time (364 flights)85February 2026: 87% on-time (323 flights)87Feb 2026March 2026: 88% on-time (443 flights)88April 2026: 86% on-time (558 flights)86May 2026: 84% on-time (589 flights)84May 2026June 2026: 80% on-time (595 flights)80July 2026: 80% on-time (629 flights)80

Best time of day to depart from STS

On-time percentage by scheduled departure hour at STS6 a.m.: 94% on-time (756 flights)67 a.m.: 92% on-time (1,071 flights)78 a.m.: 90% on-time (203 flights)89 a.m.: 78% on-time (327 flights)910 a.m.: 80% on-time (707 flights)1011 a.m.: 83% on-time (766 flights)1112 p.m.: 76% on-time (1,140 flights)121 p.m.: 76% on-time (474 flights)132 p.m.: 76% on-time (1,093 flights)143 p.m.: 76% on-time (580 flights)154 p.m.: 81% on-time (1,114 flights)165 p.m.: 76% on-time (315 flights)176 p.m.: 79% on-time (729 flights)187 p.m.: 76% on-time (773 flights)198 p.m.: 65% on-time (234 flights)20scheduled departure hour

By day of week

DayOn-timeAvg delay
Monday73%17 min
Tuesday83%12 min
Wednesday82%10 min
Thursday75%17 min
Friday73%20 min
Saturdaybest83%12 min
Sunday75%18 min

Next: compare the busiest routes from STS ↓

Busiest routes from STS

RouteFlights/12moOn-timeAvg delay
STS → SAN (San Diego)1,00972%17 min
STS → SNA (Santa Ana)74577%16 min
STS → LAX (Los Angeles)72682%12 min
STS → PHX (Phoenix)69378%17 min
STS → BUR (Burbank)67179%12 min
STS → PDX (Portland)60987%10 min
STS → SEA (Seattle)46371%16 min
STS → LAS (Las Vegas)34678%17 min
STS → DFW (Dallas/Fort Worth)18666%35 min
STS → PSP (Palm Springs)14282%15 min
STS → ONT (Ontario)10889%9 min

Compare airlines departing STS ↓

Where flights into STS come from

RouteFlights/12moOn-timeAvg delay
SAN (San Diego) → STS1,01474%14 min
SNA (Santa Ana) → STS74578%14 min
LAX (Los Angeles) → STS72884%11 min
PHX (Phoenix) → STS69382%10 min
BUR (Burbank) → STS67181%10 min
PDX (Portland) → STS64081%11 min
SEA (Seattle) → STS42877%13 min
LAS (Las Vegas) → STS34672%18 min

Most reliable routes

  1. STS → ONT89%
  2. STS → PDX87%
  3. STS → PSP82%
  4. STS → LAX82%
  5. STS → BUR79%

Most delay-prone routes

  1. STS → DFW66%
  2. STS → SEA71%
  3. STS → SAN72%
  4. STS → SNA77%
  5. STS → LAS78%

What causes delays at STS

Share of total delay minutes by cause, as reported by carriers to the US DOT, weighted across routes departing STS.

  • Late-arriving aircraft47%
  • Airline operations27%
  • National airspace system18%
  • Weather9%

Alternative airports near Santa Rosa

Other airports within 120 miles, compared on departure reliability.

AirportDistanceOn-time departuresAvg delay
OAK — Oakland San Francisco Bay Airport63 mi79%12 min
SFO — San Francisco International Airport66 mi78%16 min
SMF — Sacramento International Airport67 mi82%12 min
SJC — Mineta San Jose International Airport93 mi83%11 min
SCK — Stockton Metropolitan Airport96 mi66%36 min

Compare the airport-level record first, then check the exact route you plan to book.

Airline performance at STS

AirlineOn-time departuresAvg delayFlights
Envoy Air82%11 min805
SkyWest Airlines82%13 min7,902
Alaska Airlines78%13 min699
Southwest Airlines72%17 min410
American Airlines67%35 min486

Frequently asked questions

How often are flights delayed at STS?
20% of departures from Charles M. Schulz Sonoma County Airport left 15+ minutes late between 2024-07 and 2026-07, with an average departure delay of 14 minutes. The national on-time average over the same period was 78%.
What is the best time of day to depart from STS?
Flights scheduled around 6 a.m. depart on time 94% of the time at STS, versus 65% around 8 p.m.. Booking before noon is the usual rule of thumb here.
What is the worst month for delays at STS?
In this dataset, December 2025 was the weakest month at STS, with 65% of departures on time.
How often are flights cancelled at STS?
1.3% of scheduled departures from STS were cancelled in this period, compared with a national rate of 1.6%.

Popular route pages from this airport

Related guides

Based on 10,302 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.