Average Weather in Richmond California, United States
In Richmond, 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 42°F to 77°F and is rarely below 35°F or above 87°F.
Based on the tourism score, the best time of year to visit Richmond for warm-weather activities is from mid June to late September.
The warm season lasts for 4.4 months, from June 5 to October 18, with an average daily high temperature above 72°F. The hottest day of the year is September 11, with an average high of 77°F and low of 55°F.
The cool season lasts for 2.1 months, from December 1 to February 6, with an average daily high temperature below 59°F. The coldest day of the year is January 1, with an average low of 42°F and high of 55°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
Monte Patria, Chile (5,791 miles away); Alhadas, Portugal (5,605 miles); and Melbourne, Australia (7,883 miles) are the far-away foreign places with temperatures most similar to Richmond (view comparison).
In Richmond, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in Richmond begins around May 21 and lasts for 5.1 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 6.9 months, ending around May 21. On January 11, the cloudiest day of the year, the sky is overcast or mostly cloudy 55% of the time, and clear, mostly clear, or partly cloudy 45% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Richmond varies significantly throughout the year.
The wetter season lasts 5.1 months, from November 4 to April 8, with a greater than 16% chance of a given day being a wet day. The chance of a wet day peaks at 31% on February 20.
The drier season lasts 6.9 months, from April 8 to November 4. The smallest chance of a wet day is 0% on July 19.
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 31% 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. Richmond experiences extreme seasonal variation in monthly rainfall.
The rainy period of the year lasts for 7.4 months, from October 3 to May 16, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around February 15, with an average total accumulation of 4.0 inches.
The rainless period of the year lasts for 4.6 months, from May 16 to October 3. The least rain falls around July 30, with an average total accumulation of 0.0 inches.
Average Monthly Rainfall
The length of the day in Richmond varies significantly over the course of the year. In 2018, the shortest day is December 21, with 9 hours, 32 minutes of daylight; the longest day is June 21, with 14 hours, 48 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, 51 minutes later at 7:37 AM on November 3. The earliest sunset is at 4:49 PM on December 6, and the latest sunset is 3 hours, 46 minutes later at 8:35 PM on June 28.
Daylight saving time (DST) is observed in Richmond 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 in Richmond, 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
The average hourly wind speed in Richmond experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 5.5 months, from March 11 to August 28, with average wind speeds of more than 8.0 miles per hour. The windiest day of the year is June 6, with an average hourly wind speed of 9.2 miles per hour.
The calmer time of year lasts for 6.5 months, from August 28 to March 11. The calmest day of the year is October 29, with an average hourly wind speed of 6.8 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Richmond varies throughout the year.
The wind is most often from the west for 9.3 months, from February 9 to November 17, with a peak percentage of 94% on August 1. The wind is most often from the north for 2.7 months, from November 17 to February 9, with a peak percentage of 37% on January 1.
Richmond 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 2.4 months, from August 7 to October 20, with an average temperature above 57°F. The day of the year with the warmest water is September 17, with an average temperature of 58°F.
The time of year with cooler water lasts for 6.0 months, from December 18 to June 17, with an average temperature below 54°F. The day of the year with the coolest water is May 3, with an average temperature of 53°F.
Average Water Temperature
Best Time of Year to Visit
To characterize how pleasant the weather is in Richmond 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 Richmond for general outdoor tourist activities is from mid June to late September, with a peak score in the third week of August.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best times of year to visit Richmond for hot-weather activities are from late June to late July and from mid August to late September, with a peak score in the first week of September.
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.
Temperatures in Richmond are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.
Time Spent in Various Temperature Bands and the Growing Season
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 7 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 27, with an average of 8.4 kWh.
The darker period of the year lasts for 3.5 months, from November 4 to February 18, with an average daily incident shortwave energy per square meter below 3.4 kWh. The darkest day of the year is December 26, with an average of 2.1 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Richmond are 37.936 deg latitude, -122.348 deg longitude, and 26 ft elevation.
The topography within 2 miles of Richmond contains only modest variations in elevation, with a maximum elevation change of 348 feet and an average elevation above sea level of 50 feet. Within 10 miles contains only modest variations in elevation (1,886 feet). Within 50 miles contains very significant variations in elevation (3,898 feet).
The area within 2 miles of Richmond is covered by artificial surfaces (95%), within 10 miles by water (48%) and artificial surfaces (27%), and within 50 miles by water (32%) and grassland (21%).
This report illustrates the typical weather in Richmond, 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
There are 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Richmond.
For each station, the records are corrected for the elevation difference between that station and Richmond according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Richmond is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Richmond and a given station.
The stations contributing to this reconstruction are: Naval Air Station Alameda (historical) (32%, 23 kilometers, south); Buchanan Field Airport (26%, 26 kilometers, east); Gnoss Field (22%, 30 kilometers, northwest); and Napa County Airport (20%, 31 kilometers, north).
Time zones for aiports and weather stations are provided by AskGeo.com .