Average Weather at Sonoma County Airport California, United States
At Sonoma County Airport, the summers are long, warm, arid, and mostly clear and the winters are short, cold, wet, and partly cloudy. Over the course of the year, the temperature typically varies from 37°F to 84°F and is rarely below 28°F or above 96°F.
Based on the tourism score, the best time of year to visit Sonoma County Airport for warm-weather activities is from mid June to mid September.
The warm season lasts for 4.3 months, from June 2 to October 11, with an average daily high temperature above 78°F. The hottest day of the year is July 1, with an average high of 84°F and low of 52°F.
The cool season lasts for 2.5 months, from November 26 to February 13, with an average daily high temperature below 61°F. The coldest day of the year is January 1, with an average low of 37°F and high of 56°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
At Sonoma County Airport, the average percentage of the sky covered by clouds experiences extreme seasonal variation over the course of the year.
The clearer part of the year at Sonoma County Airport begins around May 17 and lasts for 5.2 months, ending around October 23. On July 20, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 92% of the time, and overcast or mostly cloudy 8% of the time.
The cloudier part of the year begins around October 23 and lasts for 6.8 months, ending around May 17. On January 10, the cloudiest day of the year, the sky is overcast or mostly cloudy 58% of the time, and clear, mostly clear, or partly cloudy 42% of the time.
Cloud Cover Categories
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days at Sonoma County Airport varies significantly throughout the year.
The wetter season lasts 5.4 months, from October 31 to April 12, with a greater than 18% chance of a given day being a wet day. The chance of a wet day peaks at 35% on February 20.
The drier season lasts 6.6 months, from April 12 to October 31. The smallest chance of a wet day is 0% on July 25.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 35% on February 20.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Sonoma County Airport experiences extreme seasonal variation in monthly rainfall.
The rainy period of the year lasts for 8.2 months, from September 27 to June 2, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around February 16, with an average total accumulation of 6.0 inches.
The rainless period of the year lasts for 3.8 months, from June 2 to September 27. The least rain falls around July 29, with an average total accumulation of 0.0 inches.
Average Monthly Rainfall
The length of the day at Sonoma County Airport varies significantly over the course of the year. In 2018, the shortest day is December 21, with 9 hours, 29 minutes of daylight; the longest day is June 21, with 14 hours, 51 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:46 AM on June 14, and the latest sunrise is 1 hour, 54 minutes later at 7:40 AM on November 3. The earliest sunset is at 4:50 PM on December 7, and the latest sunset is 3 hours, 49 minutes later at 8:39 PM on June 27.
Daylight saving time (DST) is observed at Sonoma County Airport during 2018, starting in the spring on March 11, lasting 7.8 months, and ending in the fall on November 4.
Sunrise & Sunset with Twilight and Daylight Saving Time
The perceived humidity level at Sonoma County Airport, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.
Humidity Comfort Levels
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed at Sonoma County Airport experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 4.1 months, from March 10 to July 15, with average wind speeds of more than 7.3 miles per hour. The windiest day of the year is June 6, with an average hourly wind speed of 8.2 miles per hour.
The calmer time of year lasts for 7.9 months, from July 15 to March 10. The calmest day of the year is October 29, with an average hourly wind speed of 6.4 miles per hour.
Average Wind Speed
The predominant average hourly wind direction at Sonoma County Airport varies throughout the year.
The wind is most often from the west for 7.5 months, from March 3 to October 17, with a peak percentage of 78% on July 31. The wind is most often from the north for 4.5 months, from October 17 to March 3, with a peak percentage of 43% on January 1.
Sonoma County Airport is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average water temperature experiences some seasonal variation over the course of the year.
The time of year with warmer water lasts for 2.5 months, from August 16 to October 31, with an average temperature above 55°F. The day of the year with the warmest water is September 24, with an average temperature of 56°F.
The time of year with cooler water lasts for 3.1 months, from March 27 to June 30, with an average temperature below 52°F. The day of the year with the coolest water is May 12, with an average temperature of 51°F.
Average Water Temperature
Best Time of Year to Visit
To characterize how pleasant the weather is at Sonoma County Airport throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Sonoma County Airport for general outdoor tourist activities is from mid June to mid September, with a peak score in the last week of July.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Sonoma County Airport for hot-weather activities is from mid June to early August, with a peak score in the first week of July.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
The growing season at Sonoma County Airport typically lasts for 9.2 months (280 days), from around February 22 to around November 29, rarely starting before January 4 or after March 27, and rarely ending before November 8 or after December 30.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms at Sonoma County Airport should appear around February 12, only rarely appearing before February 2 or after March 2.
Growing Degree Days
The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 3.5 months, from May 9 to August 25, with an average daily incident shortwave energy per square meter above 7.2 kWh. The brightest day of the year is June 30, with an average of 8.5 kWh.
The darker period of the year lasts for 3.6 months, from November 3 to February 20, with an average daily incident shortwave energy per square meter below 3.3 kWh. The darkest day of the year is December 25, with an average of 2.0 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Sonoma County Airport are 38.509 deg latitude, -122.814 deg longitude, and 112 ft elevation.
The topography within 2 miles of Sonoma County Airport contains only modest variations in elevation, with a maximum elevation change of 105 feet and an average elevation above sea level of 99 feet. Within 10 miles contains only modest variations in elevation (1,719 feet). Within 50 miles contains very significant variations in elevation (4,813 feet).
The area within 2 miles of Sonoma County Airport is covered by cropland (68%), artificial surfaces (16%), and grassland (16%), within 10 miles by cropland (31%) and trees (25%), and within 50 miles by water (29%) and shrubs (25%).
This report illustrates the typical weather at Sonoma County Airport, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
Sonoma County Airport has a weather station that reported reliably enough during the analysis period that we have included it in our network. When available, historical temperature and dew point measurements are taken directly from this weather station. These records are obtained from NOAA's Integrated Surface Hourly data set, falling back on ICAO METAR records as required.
In the case of missing or erroneous measurements from this station, we fall back on records from nearby stations, adjusted according to typical seasonal and diurnal intra-station differences. For a given day of the year and hour of the day, the fallback station is selected to minimize the prediction error over the years for which there are measurements for both stations.
The stations on which we may fall back include but are not limited to Gnoss Field, Napa County Airport, Ukiah Municipal Airport, Nut Tree Airport, Travis Air Force Base, Buchanan Field Airport, Naval Air Station Alameda (historical), and Oakland International Airport.
Time zones for aiports and weather stations are provided by AskGeo.com .