Average Weather in December in Aberdeen Idaho, United States
Daily high temperatures decrease by 7°F, from 38°F to 32°F, rarely falling below 18°F or exceeding 51°F.
Daily low temperatures decrease by 5°F, from 23°F to 18°F, rarely falling below -0°F or exceeding 36°F. The lowest daily average low temperature is 18°F on December 30.
For reference, on July 27, the hottest day of the year, temperatures in Aberdeen typically range from 56°F to 89°F, while on December 30, the coldest day of the year, they range from 18°F to 32°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 Aberdeen experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 55% throughout the month.
The clearest day of the month is December 17, with clear, mostly clear, or partly cloudy conditions 46% of the time.
For reference, on January 17, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 58%, while on July 26, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 82%.
Cloud Cover Categories in December
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Aberdeen, the chance of a wet day over the course of December is gradually decreasing, starting the month at 17% and ending it at 14%.
For reference, the year's highest daily chance of a wet day is 20% on May 23, and its lowest chance is 5% on July 5.
Over the course of December in Aberdeen, the chance of a day with only rain decreases from 10% to 7%, the chance of a day with mixed snow and rain remains an essentially constant 3% throughout, and the chance of a day with only snow remains an essentially constant 4% throughout.
Probability of Precipitation in December
To show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day rainfall during December in Aberdeen is essentially constant, remaining about 0.6 inches throughout, and rarely exceeding 1.5 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 Aberdeen is essentially constant, remaining about 0.3 inches throughout, and rarely exceeding 0.9 inches or falling to 0.0 inches.
The highest average 31-day liquid-equivalent accumulation is 0.3 inches on December 17.
Average Monthly Liquid-Equivalent Snowfall in December
Over the course of December in Aberdeen, the length of the day is essentially constant. The shortest day of the month is December 21, with 9 hours, 1 minute of daylight and the longest day is December 1, with 9 hours, 15 minutes of daylight.
Hours of Daylight and Twilight in December
The earliest sunrise of the month in Aberdeen is 7:42 AM on December 1 and the latest sunrise is 20 minutes later at 8:02 AM on December 31.
The earliest sunset is 4:56 PM on December 9 and the latest sunset is 10 minutes later at 5:06 PM on December 31.
Daylight saving time is observed in Aberdeen 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 5:52 AM and sets 15 hours, 21 minutes later, at 9:13 PM, while on December 21, the shortest day of the year, it rises at 7:59 AM and sets 9 hours, 1 minute later, at 4:59 PM.
Sunrise & Sunset with Twilight and Daylight Saving Time in December
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
The chance that a given day will be muggy in Aberdeen is essentially constant during December, remaining around 0% throughout.
For reference, on July 22, the muggiest day of the year, there are muggy conditions 0% 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
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in Aberdeen is essentially constant during December, remaining within 0.3 miles per hour of 8.2 miles per hour throughout.
For reference, on March 29, the windiest day of the year, the daily average wind speed is 9.7 miles per hour, while on August 4, the calmest day of the year, the daily average wind speed is 7.3 miles per hour.
The lowest daily average wind speed during December is 7.9 miles per hour on December 24.
Average Wind Speed in December
Wind Direction in December
Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).
The growing season in Aberdeen typically lasts for 4.6 months (142 days), from around May 9 to around September 29, rarely starting before April 21 or after May 28, and rarely ending before September 9 or after October 21.
The month of December in Aberdeen is reliably fully outside of the growing season.
Time Spent in Various Temperature Bands and the Growing Season in December
Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.
The average accumulated growing degree days in Aberdeen are essentially constant during December, remaining around 2,522°F throughout.
Growing Degree Days in December
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy in Aberdeen is essentially constant during December, remaining within 0.1 kWh of 1.9 kWh throughout.
The lowest average daily incident shortwave solar energy during December is 1.8 kWh on December 21.
Average Daily Incident Shortwave Solar Energy in December
For the purposes of this report, the geographical coordinates of Aberdeen are 42.944 deg latitude, -112.838 deg longitude, and 4,403 ft elevation.
The topography within 2 miles of Aberdeen is essentially flat, with a maximum elevation change of 75 feet and an average elevation above sea level of 4,399 feet. Within 10 miles is essentially flat (577 feet). Within 50 miles contains significant variations in elevation (5,115 feet).
The area within 2 miles of Aberdeen is covered by cropland (97%), within 10 miles by cropland (64%) and water (22%), and within 50 miles by shrubs (58%) and cropland (21%).
This report illustrates the typical weather in Aberdeen 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 Aberdeen.
For each station, the records are corrected for the elevation difference between that station and Aberdeen 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 Aberdeen is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Aberdeen and a given station.
The stations contributing to this reconstruction are: Pocatello Regional Airport (84%, 22 kilometers, east); Burley Municipal Airport (10%, 88 kilometers, southwest); and Friedman Memorial Airport (5%, 134 kilometers, northwest).
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
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.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.