Average Weather in January in Saint Jacob Illinois, United States
Daily high temperatures are around 40°F, rarely falling below 24°F or exceeding 57°F. The lowest daily average high temperature is 39°F on January 16.
Daily low temperatures are around 25°F, rarely falling below 8°F or exceeding 39°F. The lowest daily average low temperature is 24°F on January 22.
For reference, on July 20, the hottest day of the year, temperatures in Saint Jacob typically range from 69°F to 88°F, while on January 22, the coldest day of the year, they range from 24°F to 40°F.
Average High and Low Temperature in January
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on January. 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 January
The month of January in Saint Jacob experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 52% throughout the month.
The clearest day of the month is January 16, with clear, mostly clear, or partly cloudy conditions 49% of the time.
For reference, on February 12, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 54%, while on August 27, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 71%.
Cloud Cover Categories in January
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 Saint Jacob, the chance of a wet day over the course of January is gradually decreasing, starting the month at 19% and ending it at 17%.
For reference, the year's highest daily chance of a wet day is 40% on June 7, and its lowest chance is 16% on January 28.
Over the course of January in Saint Jacob, the chance of a day with only rain decreases from 14% to 11%, 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 3% throughout.
Probability of Precipitation in January
The average sliding 31-day rainfall during January in Saint Jacob is gradually decreasing, starting the month at 2.0 inches, when it rarely exceeds 4.2 inches or falls below 0.2 inches, and ending the month at 1.7 inches, when it rarely exceeds 3.3 inches or falls below 0.3 inches.
The lowest average 31-day accumulation is 1.6 inches on January 25.
Average Monthly Rainfall in January
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 January in Saint Jacob 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 0.4 inches on January 27.
Average Monthly Liquid-Equivalent Snowfall in January
Over the course of January in Saint Jacob, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 43 minutes, implying an average daily increase of 1 minute, 26 seconds, and weekly increase of 9 minutes, 59 seconds.
The shortest day of the month is January 1, with 9 hours, 31 minutes of daylight and the longest day is January 31, with 10 hours, 14 minutes of daylight.
Hours of Daylight and Twilight in January
The latest sunrise of the month in Saint Jacob is 7:17 AM on January 6 and the earliest sunrise is 12 minutes earlier at 7:05 AM on January 31.
The earliest sunset is 4:48 PM on January 1 and the latest sunset is 31 minutes later at 5:19 PM on January 31.
Daylight saving time is observed in Saint Jacob during 2018, but it neither starts nor ends during January, so the entire month is in standard time.
For reference, on June 21, the longest day of the year, the Sun rises at 5:34 AM and sets 14 hours, 53 minutes later, at 8:27 PM, while on December 21, the shortest day of the year, it rises at 7:13 AM and sets 9 hours, 27 minutes later, at 4:40 PM.
Sunrise & Sunset with Twilight in January
The chance that a given day will be muggy in Saint Jacob is essentially constant during January, remaining around 0% throughout.
For reference, on July 24, the muggiest day of the year, there are muggy conditions 71% 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 January
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed in Saint Jacob is essentially constant during January, remaining within 0.1 miles per hour of 10.6 miles per hour throughout.
For reference, on April 1, the windiest day of the year, the daily average wind speed is 11.2 miles per hour, while on July 31, the calmest day of the year, the daily average wind speed is 6.4 miles per hour.
Average Wind Speed in January
Wind Direction in January
The growing season in Saint Jacob typically lasts for 6.7 months (207 days), from around April 4 to around October 28, rarely starting before March 16 or after April 22, and rarely ending before October 10 or after November 15.
The month of January in Saint Jacob is reliably fully outside of the growing season.
Time Spent in Various Temperature Bands and the Growing Season in January
The average accumulated growing degree days in Saint Jacob are essentially constant during January, remaining within 6°F of 6°F throughout.
Growing Degree Days in January
The average daily incident shortwave solar energy in Saint Jacob is gradually increasing during January, rising by 0.6 kWh, from 2.1 kWh to 2.7 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in January
For the purposes of this report, the geographical coordinates of Saint Jacob are 38.714 deg latitude, -89.768 deg longitude, and 499 ft elevation.
The topography within 2 miles of Saint Jacob contains only modest variations in elevation, with a maximum elevation change of 112 feet and an average elevation above sea level of 500 feet. Within 10 miles also contains only modest variations in elevation (207 feet). Within 50 miles contains only modest variations in elevation (715 feet).
The area within 2 miles of Saint Jacob is covered by cropland (85%) and trees (12%), within 10 miles by cropland (85%) and trees (11%), and within 50 miles by cropland (69%) and trees (18%).
This report illustrates the typical weather in Saint Jacob 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 Saint Jacob.
For each station, the records are corrected for the elevation difference between that station and Saint Jacob 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 Saint Jacob is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Saint Jacob and a given station.
The stations contributing to this reconstruction are: Flying L Airport (52%, 20 kilometers, south); Saint Louis Regional Airport (26%, 31 kilometers, northwest); Litchfield Municipal Airport (12%, 51 kilometers, north); and Centralia Municipal Airport (9%, 63 kilometers, east).
Time zones for aiports and weather stations are provided by AskGeo.com .