Average Weather in December in Fort St. John Canada
In Fort St. John, the month of December is characterized by falling daily high temperatures, with daily highs decreasing by 5°F, from 21°F to 17°F over the course of the month, and rarely exceeding 40°F or dropping below -10°F.
Daily low temperatures decrease by 5°F, from 8°F to 3°F, rarely falling below -21°F or exceeding 29°F.
For reference, on July 30, the hottest day of the year, temperatures in Fort St. John typically range from 53°F to 73°F, while on January 11, the coldest day of the year, they range from 3°F to 17°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 Fort St. John experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 69% throughout the month.
The clearest day of the month is December 17, with clear, mostly clear, or partly cloudy conditions 31% of the time.
For reference, on February 17, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 73%, while on August 4, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 54%.
Cloud Cover Categories in December
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Fort St. John, the chance of a wet day over the course of December is essentially constant, remaining around 20% throughout.
For reference, the year's highest daily chance of a wet day is 30% on July 4, and its lowest chance is 13% on April 5.
Over the course of December in Fort St. John, the chance of a day with only rain remains an essentially constant 2% throughout, the chance of a day with mixed snow and rain remains an essentially constant 1% throughout, and the chance of a day with only snow remains an essentially constant 16% throughout.
Probability of Precipitation in December
The average sliding 31-day rainfall during December in Fort St. John is essentially constant, remaining about 0.1 inches throughout, and rarely exceeding 0.4 inches or falling below -0.0 inches.
The lowest average 31-day accumulation is 0.1 inches on December 17.
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 Fort St. John is essentially constant, remaining about 0.8 inches throughout, and rarely exceeding 1.9 inches or falling below 0.2 inches.
Average Monthly Liquid-Equivalent Snowfall in December
Over the course of December in Fort St. John, the length of the day is gradually decreasing. From the start to the end of the month, the length of the day decreases by 19 minutes, implying an average daily decrease of 38 seconds, and weekly decrease of 4 minutes, 28 seconds.
The shortest day of the month is December 21, with 6 hours, 53 minutes of daylight and the longest day is December 1, with 7 hours, 20 minutes of daylight.
Hours of Daylight and Twilight in December
The earliest sunrise of the month in Fort St. John is 9:12 AM on December 1 and the latest sunrise is 24 minutes later at 9:36 AM on December 28.
The earliest sunset is 4:26 PM on December 14 and the latest sunset is 10 minutes later at 4:37 PM on December 31.
Daylight saving time is not observed in Fort St. John during 2017.
For reference, on June 21, the longest day of the year, the Sun rises at 4:14 AM and sets 17 hours, 41 minutes later, at 9:55 PM, while on December 21, the shortest day of the year, it rises at 9:35 AM and sets 6 hours, 53 minutes later, at 4:28 PM.
Sunrise & Sunset with Twilight in December
The chance that a given day will be muggy in Fort St. John is essentially constant during December, remaining around 0% throughout.
For reference, on July 26, 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
The average hourly wind speed in Fort St. John is essentially constant during December, remaining within 0.1 miles per hour of 4.9 miles per hour throughout.
For reference, on April 20, the windiest day of the year, the daily average wind speed is 5.0 miles per hour, while on August 1, the calmest day of the year, the daily average wind speed is 3.9 miles per hour.
Average Wind Speed in December
Wind Direction in December
The average daily incident shortwave solar energy in Fort St. John is essentially constant during December, remaining within 0.1 kWh of 0.5 kWh throughout.
The lowest average daily incident shortwave solar energy during December is 0.4 kWh on December 20.
Average Daily Incident Shortwave Solar Energy in December
For the purposes of this report, the geographical coordinates of Fort St. John are 56.250 deg latitude, -120.853 deg longitude, and 2,238 ft elevation.
The topography within 2 miles of Fort St. John contains only modest variations in elevation, with a maximum elevation change of 427 feet and an average elevation above sea level of 2,241 feet. Within 10 miles contains only modest variations in elevation (1,516 feet). Within 50 miles contains very significant variations in elevation (3,173 feet).
The area within 2 miles of Fort St. John is covered by sparse vegetation (46%), cropland (35%), and artificial surfaces (17%), within 10 miles by cropland (43%) and trees (39%), and within 50 miles by trees (62%) and cropland (27%).
This report illustrates the typical weather in Fort St. John 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 is only a single weather station, Fort St. John Airport, in our network suitable to be used as a proxy for the historical temperature and dew point records of Fort St. John.
At a distance of 7 kilometers from Fort St. John, closer than our threshold of 150 kilometers, this station is deemed sufficiently nearby to be relied upon as our primary source for temperature and dew point records.
The station records are corrected for the elevation difference between the station and Fort St. John according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
Please note that the station records themselves may additionally have been back-filled using other nearby stations or the MERRA-2 reanalysis.
Time zones for aiports and weather stations are provided by AskGeo.com .