Average Weather in January in Decatur Arkansas, United States
Daily high temperatures are around 47°F, rarely falling below 30°F or exceeding 63°F. The lowest daily average high temperature is 46°F on January 5.
Daily low temperatures are around 28°F, rarely falling below 12°F or exceeding 44°F. The lowest daily average low temperature is 28°F on January 6.
For reference, on July 25, the hottest day of the year, temperatures in Decatur typically range from 69°F to 90°F, while on January 6, the coldest day of the year, they range from 28°F to 46°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 Decatur experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 47% throughout the month.
The clearest day of the month is January 16, with clear, mostly clear, or partly cloudy conditions 54% of the time.
For reference, on February 12, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 50%, while on July 29, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 71%.
Cloud Cover Categories in January
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Decatur, the chance of a wet day over the course of January is essentially constant, remaining around 15% throughout.
For reference, the year's highest daily chance of a wet day is 44% on May 27, and its lowest chance is 14% on January 13.
Over the course of January in Decatur, the chance of a day with only rain remains an essentially constant 10% throughout, 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 2% throughout.
Probability of Precipitation in January
The average sliding 31-day rainfall during January in Decatur is gradually decreasing, starting the month at 2.0 inches, when it rarely exceeds 5.2 inches or falls below 0.2 inches, and ending the month at 1.6 inches, when it rarely exceeds 3.5 inches or falls below 0.2 inches.
The lowest average 31-day accumulation is 1.6 inches on January 23.
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 Decatur is essentially constant, remaining about 0.2 inches throughout, and rarely exceeding 0.7 inches or falling below -0.0 inches.
The highest average 31-day liquid-equivalent accumulation is 0.3 inches on January 27.
Average Monthly Liquid-Equivalent Snowfall in January
Over the course of January in Decatur, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 39 minutes, implying an average daily increase of 1 minute, 18 seconds, and weekly increase of 9 minutes, 6 seconds.
The shortest day of the month is January 1, with 9 hours, 44 minutes of daylight and the longest day is January 31, with 10 hours, 23 minutes of daylight.
Hours of Daylight and Twilight in January
The latest sunrise of the month in Decatur is 7:29 AM on January 6 and the earliest sunrise is 10 minutes earlier at 7:19 AM on January 31.
The earliest sunset is 5:13 PM on January 1 and the latest sunset is 29 minutes later at 5:43 PM on January 31.
Daylight saving time is observed in Decatur 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 6:00 AM and sets 14 hours, 38 minutes later, at 8:38 PM, while on December 21, the shortest day of the year, it rises at 7:25 AM and sets 9 hours, 41 minutes later, at 5:06 PM.
Sunrise & Sunset with Twilight in January
The chance that a given day will be muggy in Decatur is essentially constant during January, remaining around 0% throughout.
For reference, on July 16, the muggiest day of the year, there are muggy conditions 74% of the time, while on December 12, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in January
The average hourly wind speed in Decatur is essentially constant during January, remaining within 0.1 miles per hour of 7.7 miles per hour throughout.
For reference, on March 19, the windiest day of the year, the daily average wind speed is 8.5 miles per hour, while on August 3, the calmest day of the year, the daily average wind speed is 5.1 miles per hour.
Average Wind Speed in January
Wind Direction in January
The growing season in Decatur typically lasts for 6.6 months (202 days), from around April 9 to around October 28, rarely starting before March 19 or after April 29, and rarely ending before October 10 or after November 16.
The month of January in Decatur 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 Decatur are essentially constant during January, remaining within 15°F of 15°F throughout.
Growing Degree Days in January
The average daily incident shortwave solar energy in Decatur is gradually increasing during January, rising by 0.6 kWh, from 2.4 kWh to 3.0 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 Decatur are 36.336 deg latitude, -94.461 deg longitude, and 1,240 ft elevation.
The topography within 2 miles of Decatur contains only modest variations in elevation, with a maximum elevation change of 348 feet and an average elevation above sea level of 1,255 feet. Within 10 miles contains only modest variations in elevation (581 feet). Within 50 miles contains significant variations in elevation (1,890 feet).
The area within 2 miles of Decatur is covered by cropland (83%) and trees (17%), within 10 miles by cropland (72%) and trees (27%), and within 50 miles by trees (48%) and cropland (47%).
This report illustrates the typical weather in Decatur 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 Decatur.
For each station, the records are corrected for the elevation difference between that station and Decatur 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 Decatur is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Decatur and a given station.
The stations contributing to this reconstruction are: Northwest Arkansas Regional Airport (46%, 16 kilometers, east); Smith Field (43%, 16 kilometers, south); and Grove Municipal Airport (11%, 39 kilometers, northwest).
Time zones for aiports and weather stations are provided by AskGeo.com .