Average Weather in May in Perris California, United States
Daily high temperatures increase by 4°F, from 76°F to 80°F, rarely falling below 65°F or exceeding 91°F.
Daily low temperatures increase by 4°F, from 51°F to 55°F, rarely falling below 45°F or exceeding 60°F.
For reference, on August 19, the hottest day of the year, temperatures in Perris typically range from 64°F to 92°F, while on December 25, the coldest day of the year, they range from 41°F to 64°F.
Average High and Low Temperature in May
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on May. The horizontal axis is the day, 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 May
The month of May in Perris experiences gradually decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 26% to 20%.
The clearest day of the month is May 31, with clear, mostly clear, or partly cloudy conditions 80% of the time.
For reference, on February 20, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 45%, while on September 7, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 90%.
Cloud Cover Categories in May
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. In Perris, the chance of a wet day over the course of May is decreasing, starting the month at 5% and ending it at 1%.
For reference, the year's highest daily chance of a wet day is 20% on February 20, and its lowest chance is 1% on June 21.
Probability of Precipitation in May
The average sliding 31-day rainfall during May in Perris is essentially constant, remaining about 0.2 inches throughout, and rarely exceeding 0.9 inches.
Average Monthly Rainfall in May
Over the course of May in Perris, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 42 minutes, implying an average daily increase of 1 minute, 25 seconds, and weekly increase of 9 minutes, 52 seconds.
The shortest day of the month is May 1, with 13 hours, 32 minutes of daylight and the longest day is May 31, with 14 hours, 14 minutes of daylight.
Hours of Daylight and Twilight in May
The latest sunrise of the month in Perris is 6:00 AM on May 1 and the earliest sunrise is 21 minutes earlier at 5:39 AM on May 31.
The earliest sunset is 7:32 PM on May 1 and the latest sunset is 22 minutes later at 7:53 PM on May 31.
Daylight saving time is observed in Perris during 2019, but it neither starts nor ends during May, so the entire month is in daylight saving time.
For reference, on June 21, the longest day of the year, the Sun rises at 5:38 AM and sets 14 hours, 24 minutes later, at 8:02 PM, while on December 22, the shortest day of the year, it rises at 6:50 AM and sets 9 hours, 54 minutes later, at 4:44 PM.
Sunrise & Sunset with Twilight in May
The chance that a given day will be muggy in Perris is essentially constant during May, remaining around 0% throughout.
For reference, on August 6, the muggiest day of the year, there are muggy conditions 3% of the time, while on November 3, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in May
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed in Perris is essentially constant during May, remaining within 0.2 miles per hour of 6.2 miles per hour throughout.
For reference, on December 31, the windiest day of the year, the daily average wind speed is 6.6 miles per hour, while on September 8, the calmest day of the year, the daily average wind speed is 4.8 miles per hour.
Average Wind Speed in May
Wind Direction in May
Perris 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 surface water temperature in Perris is gradually increasing during May, rising by 2°F, from 62°F to 64°F, over the course of the month.
Average Water Temperature in May
The growing season in Perris typically lasts for 12 months (354 days), from around January 10 to around December 30, rarely starting after March 1, or ending before November 28.
The month of May in Perris is reliably fully within the growing season.
Time Spent in Various Temperature Bands and the Growing Season in May
The average accumulated growing degree days in Perris are increasing during May, increasing by 430°F, from 872°F to 1,302°F, over the course of the month.
Growing Degree Days in May
The average daily incident shortwave solar energy in Perris is gradually increasing during May, rising by 0.7 kWh, from 7.7 kWh to 8.3 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in May
For the purposes of this report, the geographical coordinates of Perris are 33.783 deg latitude, -117.229 deg longitude, and 1,440 ft elevation.
The topography within 2 miles of Perris contains only modest variations in elevation, with a maximum elevation change of 456 feet and an average elevation above sea level of 1,487 feet. Within 10 miles contains only modest variations in elevation (1,503 feet). Within 50 miles contains very significant variations in elevation (11,457 feet).
The area within 2 miles of Perris is covered by shrubs (70%), grassland (16%), and cropland (12%), within 10 miles by shrubs (65%) and grassland (26%), and within 50 miles by shrubs (57%) and artificial surfaces (16%).
This report illustrates the typical weather in Perris year round, 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 Perris.
For each station, the records are corrected for the elevation difference between that station and Perris 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 Perris is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Perris and a given station.
The stations contributing to this reconstruction are: March Air Reserve Base (86%, 13 kilometers, north); Oceanside, Camp Pendleton, Marine Corps Air Station (7%, 55 kilometers, south); and Palm Springs International Airport (7%, 67 kilometers, east).
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Time zones for aiports and weather stations are provided by AskGeo.com .