Average Weather in December in Sibley Iowa, United States
Daily high temperatures decrease by 9°F, from 35°F to 26°F, rarely falling below 8°F or exceeding 50°F.
Daily low temperatures decrease by 9°F, from 19°F to 11°F, rarely falling below -9°F or exceeding 33°F.
For reference, on July 5, the hottest day of the year, temperatures in Sibley typically range from 62°F to 83°F, while on January 15, the coldest day of the year, they range from 10°F to 26°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 Sibley experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 54% throughout the month. The highest chance of overcast or mostly cloudy conditions is 56% on December 29.
The clearest day of the month is December 1, with clear, mostly clear, or partly cloudy conditions 47% of the time.
For reference, on February 3, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 56%, while on July 28, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 74%.
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 Sibley, the chance of a wet day over the course of December is gradually decreasing, starting the month at 11% and ending it at 8%.
For reference, the year's highest daily chance of a wet day is 41% on June 7, and its lowest chance is 6% on February 12.
Over the course of December in Sibley, the chance of a day with only rain decreases from 4% to 1%, 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 6% throughout.
Probability of Precipitation in December
The average sliding 31-day rainfall during December in Sibley is gradually decreasing, starting the month at 0.4 inches, when it rarely exceeds 1.2 inches, and ending the month at 0.1 inches, when it rarely exceeds 0.4 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 Sibley is essentially constant, remaining about 0.4 inches throughout, and rarely exceeding 1.0 inches or falling to 0.0 inches.
The highest average 31-day liquid-equivalent accumulation is 0.4 inches on December 13.
Average Monthly Liquid-Equivalent Snowfall in December
Over the course of December in Sibley, the length of the day is essentially constant. The shortest day of the month is December 21, with 8 hours, 57 minutes of daylight and the longest day is December 1, with 9 hours, 12 minutes of daylight.
Hours of Daylight and Twilight in December
The earliest sunrise of the month in Sibley is 7:35 AM on December 1 and the latest sunrise is 20 minutes later at 7:55 AM on December 31.
The earliest sunset is 4:46 PM on December 9 and the latest sunset is 10 minutes later at 4:56 PM on December 31.
Daylight saving time is observed in Sibley 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 15 hours, 25 minutes later, at 9:07 PM, while on December 21, the shortest day of the year, it rises at 7:52 AM and sets 8 hours, 57 minutes later, at 4:49 PM.
Sunrise & Sunset with Twilight and Daylight Saving Time in December
The chance that a given day will be muggy in Sibley is essentially constant during December, remaining around 0% throughout.
For reference, on July 21, the muggiest day of the year, there are muggy conditions 42% of the time, while on November 8, 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 Sibley is essentially constant during December, remaining within 0.2 miles per hour of 12.0 miles per hour throughout.
For reference, on April 8, the windiest day of the year, the daily average wind speed is 13.6 miles per hour, while on August 3, the calmest day of the year, the daily average wind speed is 8.8 miles per hour.
Average Wind Speed in December
Wind Direction in December
The growing season in Sibley typically lasts for 5.0 months (154 days), from around April 29 to around September 30, rarely starting before April 10 or after May 17, and rarely ending before September 13 or after October 19.
The month of December in Sibley 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 Sibley are essentially constant during December, remaining within 1°F of 2,796°F throughout.
Growing Degree Days in December
The average daily incident shortwave solar energy in Sibley is essentially constant during December, remaining within 0.1 kWh of 1.7 kWh throughout.
The lowest average daily incident shortwave solar energy during December is 1.7 kWh on December 19.
Average Daily Incident Shortwave Solar Energy in December
For the purposes of this report, the geographical coordinates of Sibley are 43.399 deg latitude, -95.752 deg longitude, and 1,535 ft elevation.
The topography within 2 miles of Sibley is essentially flat, with a maximum elevation change of 95 feet and an average elevation above sea level of 1,523 feet. Within 10 miles is essentially flat (305 feet). Within 50 miles contains only modest variations in elevation (778 feet).
The area within 2 miles of Sibley is covered by cropland (95%), within 10 miles by cropland (100%), and within 50 miles by cropland (98%).
This report illustrates the typical weather in Sibley 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 Sibley.
For each station, the records are corrected for the elevation difference between that station and Sibley 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 Sibley is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Sibley and a given station.
The stations contributing to this reconstruction are: Sheldon (44%, 22 kilometers, south); Worthington Municipal Airport (28%, 31 kilometers, northeast); Luverne, Quentin Aanenson Field Airport (16%, 45 kilometers, northwest); and Spencer Municipal Airport (13%, 52 kilometers, southeast).
Time zones for aiports and weather stations are provided by AskGeo.com .