Average Weather in December in Ritzville Washington, United States
Daily high temperatures decrease by 5°F, from 38°F to 33°F, rarely falling below 21°F or exceeding 49°F. The lowest daily average high temperature is 33°F on December 29.
Daily low temperatures decrease by 4°F, from 28°F to 25°F, rarely falling below 12°F or exceeding 38°F.
For reference, on July 31, the hottest day of the year, temperatures in Ritzville typically range from 58°F to 89°F, while on December 30, the coldest day of the year, they range from 25°F to 33°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 Ritzville experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 68% throughout the month.
The clearest day of the month is December 14, with clear, mostly clear, or partly cloudy conditions 33% of the time.
For reference, on January 15, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 69%, while on August 2, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 81%.
Cloud Cover Categories in December
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Ritzville, the chance of a wet day over the course of December is decreasing, starting the month at 29% and ending it at 24%.
For reference, the year's highest daily chance of a wet day is 29% on December 1, and its lowest chance is 5% on August 17.
Over the course of December in Ritzville, the chance of a day with only rain decreases from 21% to 11%, the chance of a day with mixed snow and rain remains an essentially constant 4% throughout, and the chance of a day with only snow increases from 5% to 9%.
Probability of Precipitation in December
The average sliding 31-day rainfall during December in Ritzville is gradually decreasing, starting the month at 1.2 inches, when it rarely exceeds 2.1 inches or falls below 0.3 inches, and ending the month at 0.8 inches, when it rarely exceeds 1.6 inches or falls below 0.1 inches.
Average Monthly Rainfall in December
We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. As with rainfall, we consider the liquid-equivalent snowfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day liquid-equivalent snowfall during December in Ritzville is essentially constant, remaining about 0.3 inches throughout, and rarely exceeding 1.0 inches or falling to 0.0 inches.
Average Monthly Liquid-Equivalent Snowfall in December
Over the course of December in Ritzville, the length of the day is essentially constant. The shortest day of the month is December 21, with 8 hours, 29 minutes of daylight and the longest day is December 1, with 8 hours, 47 minutes of daylight.
Hours of Daylight and Twilight in December
The earliest sunrise of the month in Ritzville is 7:19 AM on December 1 and the latest sunrise is 21 minutes later at 7:39 AM on December 31.
The earliest sunset is 4:03 PM on December 11 and the latest sunset is 10 minutes later at 4:13 PM on December 31.
Daylight saving time is observed in Ritzville 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 4:57 AM and sets 15 hours, 55 minutes later, at 8:52 PM, while on December 21, the shortest day of the year, it rises at 7:36 AM and sets 8 hours, 29 minutes later, at 4:06 PM.
Sunrise & Sunset with Twilight and Daylight Saving Time in December
The chance that a given day will be muggy in Ritzville is essentially constant during December, remaining around 0% throughout.
Humidity Comfort Levels in December
The average hourly wind speed in Ritzville is gradually decreasing during December, decreasing from 9.1 miles per hour to 8.5 miles per hour over the course of the month.
For reference, on March 26, the windiest day of the year, the daily average wind speed is 9.3 miles per hour, while on August 12, the calmest day of the year, the daily average wind speed is 7.2 miles per hour.
Average Wind Speed in December
Wind Direction in December
The growing season in Ritzville typically lasts for 5.8 months (175 days), from around April 23 to around October 16, rarely starting before April 1 or after May 14, and rarely ending before September 28 or after November 3.
The month of December in Ritzville is reliably fully outside of the growing season.
Time Spent in Various Temperature Bands and the Growing Season in December
The average accumulated growing degree days in Ritzville are essentially constant during December, remaining within 1°F of 2,584°F throughout.
Growing Degree Days in December
The average daily incident shortwave solar energy in Ritzville is essentially constant during December, remaining within 0.1 kWh of 1.2 kWh throughout.
The lowest average daily incident shortwave solar energy during December is 1.1 kWh on December 24.
Average Daily Incident Shortwave Solar Energy in December
For the purposes of this report, the geographical coordinates of Ritzville are 47.127 deg latitude, -118.380 deg longitude, and 1,870 ft elevation.
The topography within 2 miles of Ritzville contains only modest variations in elevation, with a maximum elevation change of 180 feet and an average elevation above sea level of 1,862 feet. Within 10 miles contains only modest variations in elevation (522 feet). Within 50 miles contains significant variations in elevation (2,598 feet).
The area within 2 miles of Ritzville is covered by shrubs (40%), cropland (40%), and grassland (20%), within 10 miles by shrubs (44%) and cropland (43%), and within 50 miles by shrubs (41%) and cropland (41%).
This report illustrates the typical weather in Ritzville 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 5 weather stations near enough to contribute to our estimation of the temperature and dew point in Ritzville.
For each station, the records are corrected for the elevation difference between that station and Ritzville 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 Ritzville is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Ritzville and a given station.
The stations contributing to this reconstruction are: Grant County International Airport (29%, 72 kilometers, west); Fairchild Air Force Base (26%, 79 kilometers, northeast); Pullman–Moscow Regional Airport (17%, 106 kilometers, southeast); Tri-Cities Airport (14%, 111 kilometers, southwest); and Walla Walla Regional Airport (15%, 115 kilometers, south).
Time zones for aiports and weather stations are provided by AskGeo.com .