Average Weather in December in Stevenson Ranch California, United States
Daily high temperatures decrease by 4°F, from 66°F to 62°F, rarely falling below 52°F or exceeding 76°F. The lowest daily average high temperature is 61°F on December 25.
Daily low temperatures decrease by 2°F, from 47°F to 45°F, rarely falling below 37°F or exceeding 54°F. The lowest daily average low temperature is 44°F on December 24.
For reference, on July 27, the hottest day of the year, temperatures in Stevenson Ranch typically range from 64°F to 94°F, while on December 24, the coldest day of the year, they range from 44°F to 61°F.
Average High and Low Temperature in December
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on December. 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 December
The month of December in Stevenson Ranch experiences gradually increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 37% to 42%. The highest chance of overcast or mostly cloudy conditions is 43% on December 28.
The clearest day of the month is December 1, with clear, mostly clear, or partly cloudy conditions 63% of the time.
For reference, on February 22, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 46%, while on August 23, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 91%.
Cloud Cover Categories in December
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Stevenson Ranch, the chance of a wet day over the course of December is rapidly increasing, starting the month at 11% and ending it at 17%.
For reference, the year's highest daily chance of a wet day is 21% on February 20, and its lowest chance is 0% on July 2.
Probability of Precipitation in December
The average sliding 31-day rainfall during December in Stevenson Ranch is rapidly increasing, starting the month at 1.4 inches, when it rarely exceeds 3.3 inches or falls below 0.1 inches, and ending the month at 2.5 inches, when it rarely exceeds 6.4 inches or falls below 0.1 inches.
Average Monthly Rainfall in December
Over the course of December in Stevenson Ranch, the length of the day is essentially constant. The shortest day of the month is December 21, with 9 hours, 51 minutes of daylight and the longest day is December 1, with 10 hours, 2 minutes of daylight.
Hours of Daylight and Twilight in December
The earliest sunrise of the month in Stevenson Ranch is 6:42 AM on December 1 and the latest sunrise is 18 minutes later at 7:00 AM on December 31.
The earliest sunset is 4:43 PM on December 5 and the latest sunset is 11 minutes later at 4:54 PM on December 31.
Daylight saving time is observed in Stevenson Ranch during 2018, but it neither starts nor ends during December, so the entire month is in standard time.
For reference, on June 21, the longest day of the year, the Sun rises at 5:42 AM and sets 14 hours, 27 minutes later, at 8:09 PM, while on December 21, the shortest day of the year, it rises at 6:56 AM and sets 9 hours, 51 minutes later, at 4:48 PM.
Sunrise & Sunset with Twilight and Daylight Saving Time in December
The chance that a given day will be muggy in Stevenson Ranch is essentially constant during December, remaining around 0% throughout.
For reference, on August 3, the muggiest day of the year, there are muggy conditions 3% 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 December
The average hourly wind speed in Stevenson Ranch is gradually increasing during December, increasing from 8.6 miles per hour to 9.1 miles per hour over the course of the month.
For reference, on December 30, the windiest day of the year, the daily average wind speed is 9.1 miles per hour, while on August 9, the calmest day of the year, the daily average wind speed is 5.4 miles per hour.
The highest daily average wind speed during December is 9.1 miles per hour on December 30.
Average Wind Speed in December
Wind Direction in December
Stevenson Ranch 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 Stevenson Ranch is gradually decreasing during December, falling by 2°F, from 61°F to 59°F, over the course of the month.
Average Water Temperature in December
While it does not do so every year, freezing temperatures are seen in Stevenson Ranch over some winters. The day least likely to be in the growing season is January 16, with a 79% chance.
Time Spent in Various Temperature Bands and the Growing Season in December
The average accumulated growing degree days in Stevenson Ranch are gradually increasing during December, increasing by 140°F, from 5,072°F to 5,213°F, over the course of the month.
Growing Degree Days in December
The average daily incident shortwave solar energy in Stevenson Ranch is essentially constant during December, remaining within 0.2 kWh of 3.1 kWh throughout.
The lowest average daily incident shortwave solar energy during December is 2.9 kWh on December 26.
Average Daily Incident Shortwave Solar Energy in December
For the purposes of this report, the geographical coordinates of Stevenson Ranch are 34.390 deg latitude, -118.574 deg longitude, and 1,348 ft elevation.
The topography within 2 miles of Stevenson Ranch contains very significant variations in elevation, with a maximum elevation change of 922 feet and an average elevation above sea level of 1,396 feet. Within 10 miles contains very significant variations in elevation (3,310 feet). Within 50 miles also contains extreme variations in elevation (9,311 feet).
The area within 2 miles of Stevenson Ranch is covered by artificial surfaces (62%) and shrubs (37%), within 10 miles by shrubs (66%) and grassland (17%), and within 50 miles by shrubs (46%) and artificial surfaces (16%).
This report illustrates the typical weather in Stevenson Ranch 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 Stevenson Ranch.
For each station, the records are corrected for the elevation difference between that station and Stevenson Ranch 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 Stevenson Ranch is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Stevenson Ranch and a given station.
The stations contributing to this reconstruction are: Newhall (98%, 2.3 kilometers, south); Sandberg (0.4%, 42 kilometers, north); General Wm J Fox Airfield (1.0%, 51 kilometers, northeast); and Palmdale United States Air Force Plant 42 Airport (0.9%, 52 kilometers, northeast).
Time zones for aiports and weather stations are provided by AskGeo.com .