ICAO KSTS

Santa Rosa Charles M. Schulz Sonoma County, California (STS)

Charles M. Schulz Sonoma County Airport handled 95,991 passengers in July 2026, up 26.8% on a year earlier, according to the US BTS.

Flights (arrivals + departures) over time

The most recent periods19 periods
PeriodFlights (arrivals + departures) 2025Flights (arrivals + departures) 2026Change vs last year
January831851▲ 2.4%
February725766▲ 5.7%
March9451,016▲ 7.5%
April9791,250▲ 27.7%
May1,0291,349▲ 31.1%
June1,0441,370▲ 31.2%
July1,0591,428▲ 34.8%
August1,034––
September972––
October1,047–in progress
November1,050––
December925––
Year to date (Jan–Jul)6,6128,030▲ 21.4%

Passengers over time

Full count · domestic + international
The most recent periods19 periods
PeriodPassengers 2025Passengers 2026Change vs last year
January52,36047,924▼ 8.5%
February49,17647,205▼ 4.0%
March64,46262,936▼ 2.4%
April66,16479,265▲ 19.8%
May70,06988,331▲ 26.1%
June73,24793,385▲ 27.5%
July75,69395,991▲ 26.8%
August70,869––
September63,500––
October66,907–in progress
November63,344––
December56,807––
Year to date (Jan–Jul)451,171515,037▲ 14.2%

Tonnes of cargo over time

Full count · domestic + international
The most recent periods19 periods
PeriodTonnes of cargo 2025Tonnes of cargo 2026Change vs last year
January00▲ 75.9%
February00▲ 1,394.1%
March00▼ 56.7%
April00▲ 193.2%
May00▼ 32.7%
June00▲ 63.0%
July00▲ 85.1%
August0––
September0––
October0–in progress
November0––
December0––
Year to date (Jan–Jul)11▲ 64.5%

Seats offered over time

Full count · domestic + international
The most recent periods19 periods
PeriodSeats offered 2025Seats offered 2026Change vs last year
January74,34069,704▼ 6.2%
February65,49960,070▼ 8.3%
March86,37979,236▼ 8.3%
April87,775108,927▲ 24.1%
May95,333123,757▲ 29.8%
June96,644125,929▲ 30.3%
July99,125129,672▲ 30.8%
August91,937––
September83,761––
October84,865–in progress
November84,322––
December75,174––
Year to date (Jan–Jul)605,095697,295▲ 15.2%

Load factor (computed)

Full count · domestic + international

Passengers ÷ seats offered, both as reported by the US BTS for the same months. Computed by us; the two source series are shown on this page.

The most recent periods19 periods
PeriodLoad factor 2025Load factor 2026Change vs last year
January70.4%68.8%▼ 2.4%
February75.1%78.6%▲ 4.7%
March74.6%79.4%▲ 6.4%
April75.4%72.8%▼ 3.5%
May73.5%71.4%▼ 2.9%
June75.8%74.2%▼ 2.2%
July76.4%74.0%▼ 3.1%
August77.1%––
September75.8%––
October78.8%–in progress
November75.1%––
December75.6%––
Year-to-date average (Jan–Jul)74.5%74.2%▼ 0.4%

Seasonality · flights (arrivals + departures) by month

Year JanFebMarAprMayJunJulAugSepOctNovDec
2024 594 584 704 789 940 939 955 971 905 1,096 1,141 1,106
2025 831 725 945 979 1,029 1,044 1,059 1,034 972 1,047 1,050 925
2026 851 766 1,016 1,250 1,349 1,370 1,428
Series depth 36 years from 1990

Busiest destinations

Flights recorded between Oct 12, 2024 and Jul 31, 2026, counted from flight records published by the US BTS. Not a current timetable.

On-time departures by month

US domestic sectors recorded by BTS

80.8% of 621 timed departures from Charles M. Schulz Sonoma County Airport left within 15 minutes of schedule in July 2026, according to the US BTS. Cancelled flights are excluded.

The most recent periods19 periods
PeriodOn-time departures 2025On-time departures 2026Change vs last year
January83.9%85.5%▲ 1.9%
February79.6%86.6%▲ 8.8%
March82.4%88.0%▲ 6.8%
April80.4%86.9%▲ 8.1%
May80.4%83.8%▲ 4.2%
June74.3%80.9%▲ 8.9%
July72.7%80.8%▲ 11.3%
August80.6%––
September81.9%––
October84.5%–in progress
November81.2%––
December65.7%––
Year-to-date average (Jan–Jul)79.1%84.7%▲ 7.0%

Flight timing & delays

Historical departures, grouped by the scheduled local time at the departure airport. These are recorded outcomes, not a forecast for your flight.

US domestic sectors recorded by BTS

Source: the US BTS · Oct 12, 2024 → Jul 31, 2026

Lowest average delay06:00–07:001.3min · 652 recorded · 610 measured
Gap to highest-delay hour17.0min06:00 ↔ 20:00
Recorded flights9,179Charles M. Schulz Sonoma County Airport

Departure hour

On-time departures Partial coverage: domestic flights only

Hover, tap or focus a point to see its value, sample and source.

Average departure delay Partial coverage: domestic flights only

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Recorded flights Partial coverage: domestic flights only

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View the figures
Departure hourOn-time departuresAverage departure delayWith departure timeRecorded flights
00:00No observations———
01:00No observations———
02:00No observations———
03:00No observations———
04:00No observations———
05:00No observations———
06:0094.4%1.3 min610652
07:0092.1%3.2 min943980
08:00Fewer than 200 measured departures—189192
09:0078.1%17.3 min324327
10:0079.1%11.6 min550554
11:0084.1%9.6 min710713
12:0077.4%16.1 min1,0701,071
13:0075.0%16.8 min440441
14:0076.7%11.4 min988993
15:0076.4%12.5 min423427
16:0080.4%7.8 min975977
17:0076.2%11.9 min315315
18:0080.0%10.9 min599607
19:0075.8%11.6 min673683
20:0065.9%18.2 min223227
21:00Fewer than 200 measured departures—1920
22:00No observations———
23:00No observations———

Day of week

On-time departures Partial coverage: domestic flights only

Hover, tap or focus a point to see its value, sample and source.

Average departure delay Partial coverage: domestic flights only

Hover, tap or focus a point to see its value, sample and source.

Recorded flights Partial coverage: domestic flights only

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View the figures
Day of weekOn-time departuresAverage departure delayWith departure timeRecorded flights
Monday78.6%11.7 min1,3991,418
Tuesday84.7%6.2 min1,1311,158
Wednesday84.8%4.6 min1,1621,171
Thursday80.2%12.0 min1,3861,400
Friday76.8%14.2 min1,3981,418
Saturday84.2%8.4 min1,1781,203
Sunday78.4%14.0 min1,3971,411

Month of year

Months combine the same calendar month across the years shown; this is a seasonal pattern, not a monthly time series.

On-time departures Partial coverage: domestic flights only

Hover, tap or focus a point to see its value, sample and source.

Average departure delay Partial coverage: domestic flights only

Hover, tap or focus a point to see its value, sample and source.

Recorded flights Partial coverage: domestic flights only

Hover, tap or focus a point to see its value, sample and source.

View the figures
Month of yearOn-time departuresAverage departure delayWith departure timeRecorded flights
Jan84.8%6.8 min618643
Feb83.6%9.1 min560573
Mar85.7%6.4 min760762
Apr84.4%6.6 min920921
May82.3%8.4 min1,0421,044
Jun78.3%12.9 min994999
Jul77.7%14.5 min1,0051,014
Aug80.6%8.4 min433435
Sep81.9%11.8 min481484
Oct85.0%6.9 min626631
Nov78.0%10.8 min859880
Dec70.8%20.6 min753793

Delay and on-time rates need at least 200 measured departures per bucket. Smaller samples remain visible in the flight-count chart. An empty slot means no observations, not zero flights.

Recorded outcomes

  • On time 79.7% 7,314
  • Delayed >15 min 18.9% 1,737
  • Cancelled 1.4% 128
  • Missing departure time 0.0% 0

All recorded flights with a known scheduled local time, counted once. Missing actual times are shown separately.

On time means departing no more than 15 minutes after schedule. Cancelled flights and flights missing departure times are excluded from the on-time rate and average delay.

Environment

Air pollutants at the airport (EPA estimate)

Modelled estimate, not a measurement: aircraft below 3,000 ft (landing and take-off), ground support equipment and auxiliary power units, plus any stationary sources the state reported at the airport site. Cruise emissions are not included.

In 2023, the US EPA estimated 24.0 tonnes of nitrogen oxides (NOₓ) and 4.3 tonnes of fine particles (PM2.5) from activity at Charles M. Schulz Sonoma County Airport, according to the EPA National Emissions Inventory.

PollutantUnit201720202023
NOₓ (Nitrogen oxides)tonnes25.112.724.0
CO (Carbon monoxide)tonnes230165218
SO₂ (Sulphur dioxide)tonnes3.62.03.8
VOC (Volatile organic compounds)tonnes19.411.110.3
PM2.5 (Fine particles)tonnes4.13.54.3
PM10 (Particulate matter)tonnes5.04.15.2
Leadkg166115166
CO₂ (Carbon dioxide)tonnes3,86611,197—

The inventory is published every three years. Coverage changes between editions (about 19,300 airport sites in 2017, 6,000 in 2020, 12,700 in 2023), 2020 reflects the pandemic drop in traffic, and EPA updates its aircraft model between editions — so the columns are not a trend (Los Angeles: 3,562 tonnes of NOₓ in 2017, 8,810 in 2023). CO₂ is only reported for some sites in 2017, for all sites in 2020, and not at all in 2023. EPA publishes US customary units; converted here to metric tonnes (× 0.907) and, for lead, kilograms.

US EPA — National Emissions Inventory

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