Average Weather in December in Mount Angel Oregon, United States
Daily high temperatures decrease by 3°F, from 49°F to 46°F, rarely falling below 37°F or exceeding 56°F. The lowest daily average high temperature is 46°F on December 22.
Daily low temperatures decrease by 2°F, from 39°F to 36°F, rarely falling below 26°F or exceeding 47°F. The lowest daily average low temperature is 36°F on December 30.
For reference, on August 3, the hottest day of the year, temperatures in Mount Angel typically range from 57°F to 86°F, while on December 29, the coldest day of the year, they range from 36°F to 46°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 Mount Angel experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 75% throughout the month.
The clearest day of the month is December 20, with clear, mostly clear, or partly cloudy conditions 25% of the time.
For reference, on January 16, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 76%, while on August 3, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 82%.
Cloud Cover Categories in December
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 Mount Angel, the chance of a wet day over the course of December is rapidly decreasing, starting the month at 58% and ending it at 52%.
For reference, the year's highest daily chance of a wet day is 59% on November 28, and its lowest chance is 4% on August 5.
Over the course of December in Mount Angel, the chance of a day with only rain decreases from 57% to 49%, the chance of a day with mixed snow and rain remains an essentially constant 2% throughout, and the chance of a day with only snow remains an essentially constant 1% 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 Mount Angel is rapidly decreasing, starting the month at 9.3 inches, when it rarely exceeds 14.7 inches or falls below 4.1 inches, and ending the month at 8.1 inches, when it rarely exceeds 13.2 inches or falls below 3.4 inches.
The highest average 31-day accumulation is 9.3 inches on December 1.
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 Mount Angel is essentially constant, remaining about 0.1 inches throughout, and rarely exceeding 0.3 inches or falling below -0.0 inches.
The highest average 31-day liquid-equivalent accumulation is 0.1 inches on December 22.
Average Monthly Liquid-Equivalent Snowfall in December
Over the course of December in Mount Angel, the length of the day is essentially constant. The shortest day of the month is December 21, with 8 hours, 45 minutes of daylight and the longest day is December 1, with 9 hours, 1 minute of daylight.
Hours of Daylight and Twilight in December
The earliest sunrise of the month in Mount Angel is 7:29 AM on December 1 and the latest sunrise is 20 minutes later at 7:49 AM on December 31.
The earliest sunset is 4:29 PM on December 10 and the latest sunset is 10 minutes later at 4:39 PM on December 31.
Daylight saving time is observed in Mount Angel 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 5:24 AM and sets 15 hours, 38 minutes later, at 9:01 PM, while on December 21, the shortest day of the year, it rises at 7:46 AM and sets 8 hours, 45 minutes later, at 4:32 PM.
Sunrise & Sunset with Twilight and Daylight Saving Time in December
The chance that a given day will be muggy in Mount Angel is essentially constant during December, remaining around 0% throughout.
For reference, on July 13, 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
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed in Mount Angel is essentially constant during December, remaining within 0.1 miles per hour of 6.0 miles per hour throughout.
For reference, on December 3, the windiest day of the year, the daily average wind speed is 6.1 miles per hour, while on August 1, the calmest day of the year, the daily average wind speed is 4.1 miles per hour.
The highest daily average wind speed during December is 6.1 miles per hour on December 3.
Average Wind Speed in December
Wind Direction in December
Mount Angel 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 Mount Angel is essentially constant during December, remaining within 1°F of 51°F throughout.
Average Water Temperature in December
The growing season in Mount Angel typically lasts for 7.5 months (228 days), from around March 28 to around November 12, rarely starting before February 17 or after April 28, and rarely ending before October 17 or after December 13.
The month of December in Mount Angel is more likely than not fully outside of the growing season, with the chance that a given day is in the growing season rapidly decreasing from 22% to 2% over the course of the month.
Time Spent in Various Temperature Bands and the Growing Season in December
The average accumulated growing degree days in Mount Angel are essentially constant during December, remaining within 5°F of 2,561°F throughout.
Growing Degree Days in December
The average daily incident shortwave solar energy in Mount Angel is essentially constant during December, remaining around 1.1 kWh throughout.
The lowest average daily incident shortwave solar energy during December is 1.0 kWh on December 26.
Average Daily Incident Shortwave Solar Energy in December
For the purposes of this report, the geographical coordinates of Mount Angel are 45.068 deg latitude, -122.800 deg longitude, and 187 ft elevation.
The topography within 2 miles of Mount Angel contains only modest variations in elevation, with a maximum elevation change of 354 feet and an average elevation above sea level of 188 feet. Within 10 miles contains only modest variations in elevation (1,480 feet). Within 50 miles contains very significant variations in elevation (5,889 feet).
The area within 2 miles of Mount Angel is covered by cropland (94%), within 10 miles by cropland (84%), and within 50 miles by trees (41%) and cropland (29%).
This report illustrates the typical weather in Mount Angel 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 Mount Angel.
For each station, the records are corrected for the elevation difference between that station and Mount Angel 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 Mount Angel is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Mount Angel and a given station.
The stations contributing to this reconstruction are: Aurora State Airport (42%, 20 kilometers, north); McNary Field (33%, 24 kilometers, southwest); Mc Minnville Municipal Airport (24%, 30 kilometers, northwest); and Roberts Field-Redmond Municipal Airport (1.6%, 160 kilometers, southeast).
Time zones for aiports and weather stations are provided by AskGeo.com .