Average Weather in August in Rancho Cucamonga California, United States
Daily high temperatures are around 93°F, rarely falling below 84°F or exceeding 102°F. The highest daily average high temperature is 94°F on August 21.
Daily low temperatures are around 65°F, rarely falling below 59°F or exceeding 72°F. The highest daily average low temperature is 65°F on August 23.
For reference, on August 19, the hottest day of the year, temperatures in Rancho Cucamonga typically range from 65°F to 94°F, while on December 25, the coldest day of the year, they range from 43°F to 65°F.
Average High and Low Temperature in August
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on August. 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 August
The month of August in Rancho Cucamonga experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 11% throughout the month.
The clearest day of the month is August 31, with clear, mostly clear, or partly cloudy conditions 90% of the time.
For reference, on February 22, 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 August
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Rancho Cucamonga, the chance of a wet day over the course of August is essentially constant, remaining around 2% throughout.
For reference, the year's highest daily chance of a wet day is 20% on February 20, and its lowest chance is 0% on June 24.
Probability of Precipitation in August
The average sliding 31-day rainfall during August in Rancho Cucamonga is essentially constant, remaining about 0.1 inches throughout, and rarely exceeding 0.3 inches or falling below -0.0 inches.
Average Monthly Rainfall in August
Over the course of August in Rancho Cucamonga, the length of the day is decreasing. From the start to the end of the month, the length of the day decreases by 56 minutes, implying an average daily decrease of 1 minute, 51 seconds, and weekly decrease of 12 minutes, 57 seconds.
The shortest day of the month is August 31, with 12 hours, 54 minutes of daylight and the longest day is August 1, with 13 hours, 50 minutes of daylight.
Hours of Daylight and Twilight in August
The earliest sunrise of the month in Rancho Cucamonga is 6:01 AM on August 1 and the latest sunrise is 22 minutes later at 6:23 AM on August 31.
The latest sunset is 7:51 PM on August 1 and the earliest sunset is 34 minutes earlier at 7:17 PM on August 31.
Daylight saving time is observed in Rancho Cucamonga during 2018, but it neither starts nor ends during August, so the entire month is in daylight saving time.
For reference, on June 21, the longest day of the year, the Sun rises at 5:39 AM and sets 14 hours, 26 minutes later, at 8:05 PM, while on December 21, the shortest day of the year, it rises at 6:52 AM and sets 9 hours, 53 minutes later, at 4:44 PM.
Sunrise & Sunset with Twilight in August
The chance that a given day will be muggy in Rancho Cucamonga is essentially constant during August, remaining within 1% of 4% throughout.
The highest chance of a muggy day during August is 5% on August 11.
For reference, on August 11, the muggiest day of the year, there are muggy conditions 5% of the time, while on January 1, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in August
The average hourly wind speed in Rancho Cucamonga is essentially constant during August, remaining within 0.1 miles per hour of 5.4 miles per hour throughout.
For reference, on December 31, the windiest day of the year, the daily average wind speed is 7.6 miles per hour, while on September 9, the calmest day of the year, the daily average wind speed is 5.2 miles per hour.
Average Wind Speed in August
Wind Direction in August
Rancho Cucamonga 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 Rancho Cucamonga is essentially constant during August, remaining around 69°F throughout.
The highest average surface water temperature during August is 69°F on August 25.
Average Water Temperature in August
While it does not do so every year, freezing temperatures are seen in Rancho Cucamonga over some winters. The day least likely to be in the growing season is January 4, with a 74% chance.
Time Spent in Various Temperature Bands and the Growing Season in August
The average accumulated growing degree days in Rancho Cucamonga are rapidly increasing during August, increasing by 767°F, from 2,815°F to 3,582°F, over the course of the month.
Growing Degree Days in August
The average daily incident shortwave solar energy in Rancho Cucamonga is gradually decreasing during August, falling by 0.8 kWh, from 7.9 kWh to 7.1 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in August
For the purposes of this report, the geographical coordinates of Rancho Cucamonga are 34.106 deg latitude, -117.593 deg longitude, and 1,227 ft elevation.
The topography within 2 miles of Rancho Cucamonga contains significant variations in elevation, with a maximum elevation change of 492 feet and an average elevation above sea level of 1,230 feet. Within 10 miles contains significant variations in elevation (8,235 feet). Within 50 miles also contains extreme variations in elevation (11,470 feet).
The area within 2 miles of Rancho Cucamonga is covered by artificial surfaces (83%) and shrubs (17%), within 10 miles by shrubs (56%) and artificial surfaces (36%), and within 50 miles by shrubs (58%) and artificial surfaces (22%).
This report illustrates the typical weather in Rancho Cucamonga 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 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Rancho Cucamonga.
For each station, the records are corrected for the elevation difference between that station and Rancho Cucamonga 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 Rancho Cucamonga is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Rancho Cucamonga and a given station.
The stations contributing to this reconstruction are: Ontario International Airport (69%, 7 kilometers, southwest); Riverside Municipal Airport (16%, 22 kilometers, southeast); San Bernardino International Airport (11%, 33 kilometers, east); and Southern California Logistics Airport (3.2%, 56 kilometers, north).
Time zones for aiports and weather stations are provided by AskGeo.com .