Average Weather in San Jacinto California, United States
In San Jacinto, the summers are hot, arid, and mostly clear and the winters are long, cold, and partly cloudy. Over the course of the year, the temperature typically varies from 41°F to 96°F and is rarely below 33°F or above 102°F.
Based on the tourism score, the best time of year to visit San Jacinto for warm-weather activities is from late May to mid October.
The hot season lasts for 3.2 months, from June 15 to September 22, with an average daily high temperature above 89°F. The hottest day of the year is August 16, with an average high of 96°F and low of 67°F.
The cool season lasts for 3.8 months, from November 22 to March 15, with an average daily high temperature below 70°F. The coldest day of the year is December 25, with an average low of 41°F and high of 64°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
In San Jacinto, 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 San Jacinto begins around April 26 and lasts for 6.3 months, ending around November 5. On September 7, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 89% of the time, and overcast or mostly cloudy 11% of the time.
The cloudier part of the year begins around November 5 and lasts for 5.7 months, ending around April 26. On February 21, the cloudiest day of the year, the sky is overcast or mostly cloudy 47% of the time, and clear, mostly clear, or partly cloudy 53% 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 San Jacinto varies throughout the year.
The wetter season lasts 4.3 months, from November 25 to April 5, with a greater than 9% chance of a given day being a wet day. The chance of a wet day peaks at 18% on February 19.
The drier season lasts 7.7 months, from April 5 to November 25. The smallest chance of a wet day is 1% on June 15.
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 18% on February 19.
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. San Jacinto experiences significant seasonal variation in monthly rainfall.
The rainy period of the year lasts for 5.4 months, from October 31 to April 13, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around February 19, with an average total accumulation of 2.1 inches.
The rainless period of the year lasts for 6.6 months, from April 13 to October 31. The least rain falls around June 17, with an average total accumulation of 0.1 inches.
Average Monthly Rainfall
The length of the day in San Jacinto varies significantly over the course of the year. In 2018, the shortest day is December 21, with 9 hours, 54 minutes of daylight; the longest day is June 21, with 14 hours, 24 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:36 AM on June 12, and the latest sunrise is 1 hour, 32 minutes later at 7:08 AM on November 3. The earliest sunset is at 4:38 PM on December 4, and the latest sunset is 3 hours, 24 minutes later at 8:02 PM on June 29.
Daylight saving time (DST) is observed in San Jacinto 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 San Jacinto, 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, staying within 1% of 1% throughout.
Humidity Comfort Levels
The average hourly wind speed in San Jacinto experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 7.2 months, from November 22 to June 28, with average wind speeds of more than 5.9 miles per hour. The windiest day of the year is April 26, with an average hourly wind speed of 6.8 miles per hour.
The calmer time of year lasts for 4.8 months, from June 28 to November 22. The calmest day of the year is September 6, with an average hourly wind speed of 5.0 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in San Jacinto varies throughout the year.
The wind is most often from the west for 10 months, from January 26 to November 30, with a peak percentage of 79% on June 6. The wind is most often from the east for 1.9 months, from November 30 to January 26, with a peak percentage of 36% on January 1.
San Jacinto 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 3.0 months, from July 7 to October 6, with an average temperature above 68°F. The day of the year with the warmest water is August 22, with an average temperature of 70°F.
The time of year with cooler water lasts for 4.4 months, from December 8 to April 21, with an average temperature below 61°F. The day of the year with the coolest water is February 4, with an average temperature of 59°F.
Average Water Temperature
Best Time of Year to Visit
To characterize how pleasant the weather is in San Jacinto 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 San Jacinto for general outdoor tourist activities is from late May to mid October, with a peak score in the last week of June.
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 San Jacinto for hot-weather activities is from early July to early September, with a peak score in the last 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 in San Jacinto typically lasts for 11 months (347 days), from around January 13 to around December 27, rarely starting after March 2, or ending before November 24.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms in San Jacinto should appear around January 19, only rarely appearing before January 13 or after January 29.
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 April 24 to August 10, with an average daily incident shortwave energy per square meter above 7.5 kWh. The brightest day of the year is June 18, with an average of 8.7 kWh.
The darker period of the year lasts for 3.2 months, from November 6 to February 12, with an average daily incident shortwave energy per square meter below 4.2 kWh. The darkest day of the year is December 22, with an average of 3.1 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of San Jacinto are 33.784 deg latitude, -116.959 deg longitude, and 1,575 ft elevation.
The topography within 2 miles of San Jacinto contains only modest variations in elevation, with a maximum elevation change of 318 feet and an average elevation above sea level of 1,563 feet. Within 10 miles contains only modest variations in elevation (4,350 feet). Within 50 miles also contains extreme variations in elevation (11,660 feet).
The area within 2 miles of San Jacinto is covered by shrubs (87%) and grassland (12%), within 10 miles by shrubs (70%) and grassland (20%), and within 50 miles by shrubs (70%).
This report illustrates the typical weather in San Jacinto, 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 3 weather stations near enough to contribute to our estimation of the temperature and dew point in San Jacinto.
For each station, the records are corrected for the elevation difference between that station and San Jacinto 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 San Jacinto is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between San Jacinto and a given station.
The stations contributing to this reconstruction are: March Air Reserve Base (61%, 30 kilometers, northwest); Palm Springs International Airport (24%, 42 kilometers, east); and Oceanside, Camp Pendleton, Marine Corps Air Station (14%, 65 kilometers, southwest).
Time zones for aiports and weather stations are provided by AskGeo.com .