Average Weather in January in Sunnyside Washington, United States
Daily low temperatures increase by 3°F, from 26°F to 29°F, rarely falling below 13°F or exceeding 37°F.
For reference, on July 30, the hottest day of the year, temperatures in Sunnyside typically range from 62°F to 94°F, while on December 23, the coldest day of the year, they range from 26°F to 37°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 Sunnyside experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 64% throughout the month. The highest chance of overcast or mostly cloudy conditions is 65% on January 16.
The clearest day of the month is January 26, with clear, mostly clear, or partly cloudy conditions 38% of the time.
For reference, on January 16, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 65%, while on August 4, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 83%.
Cloud Cover Categories in January
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Sunnyside, the chance of a wet day over the course of January is gradually decreasing, starting the month at 20% and ending it at 18%.
For reference, the year's highest daily chance of a wet day is 23% on December 1, and its lowest chance is 2% on August 16.
Over the course of January in Sunnyside, the chance of a day with only rain increases from 8% to 12%, the chance of a day with mixed snow and rain decreases from 4% to 2%, and the chance of a day with only snow decreases from 8% to 4%.
Probability of Precipitation in January
The average sliding 31-day rainfall during January in Sunnyside is essentially constant, remaining about 0.6 inches throughout, and rarely exceeding 1.3 inches.
The lowest average 31-day accumulation is 0.5 inches on January 13.
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 Sunnyside is essentially constant, remaining about 0.3 inches throughout, and rarely exceeding 1.1 inches or falling below -0.0 inches.
Average Monthly Liquid-Equivalent Snowfall in January
Over the course of January in Sunnyside, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 58 minutes, implying an average daily increase of 1 minute, 57 seconds, and weekly increase of 13 minutes, 38 seconds.
The shortest day of the month is January 1, with 8 hours, 41 minutes of daylight and the longest day is January 31, with 9 hours, 40 minutes of daylight.
Hours of Daylight and Twilight in January
The latest sunrise of the month in Sunnyside is 7:43 AM on January 1 and the earliest sunrise is 19 minutes earlier at 7:23 AM on January 31.
The earliest sunset is 4:24 PM on January 1 and the latest sunset is 39 minutes later at 5:03 PM on January 31.
Daylight saving time is observed in Sunnyside during 2017, 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 5:07 AM and sets 15 hours, 48 minutes later, at 8:55 PM, while on December 21, the shortest day of the year, it rises at 7:40 AM and sets 8 hours, 36 minutes later, at 4:16 PM.
Sunrise & Sunset with Twilight in January
The chance that a given day will be muggy in Sunnyside is essentially constant during January, remaining around 0% throughout.
For reference, on July 15, 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 January
The average hourly wind speed in Sunnyside is essentially constant during January, remaining within 0.1 miles per hour of 7.7 miles per hour throughout.
For reference, on March 31, the windiest day of the year, the daily average wind speed is 8.7 miles per hour, while on September 9, the calmest day of the year, the daily average wind speed is 7.3 miles per hour.
Average Wind Speed in January
Wind Direction in January
The growing season in Sunnyside typically lasts for 6.2 months (188 days), from around April 13 to around October 19, rarely starting before March 24 or after May 4, and rarely ending before October 1 or after November 5.
The month of January in Sunnyside 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 Sunnyside are essentially constant during January, remaining within 2°F of 2°F throughout.
Growing Degree Days in January
The average daily incident shortwave solar energy in Sunnyside is gradually increasing during January, rising by 0.6 kWh, from 1.3 kWh to 1.9 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 Sunnyside are 46.324 deg latitude, -120.009 deg longitude, and 778 ft elevation.
The topography within 2 miles of Sunnyside contains only modest variations in elevation, with a maximum elevation change of 308 feet and an average elevation above sea level of 768 feet. Within 10 miles contains only modest variations in elevation (2,116 feet). Within 50 miles contains large variations in elevation (5,597 feet).
The area within 2 miles of Sunnyside is covered by cropland (55%) and artificial surfaces (45%), within 10 miles by cropland (61%) and shrubs (25%), and within 50 miles by shrubs (60%) and cropland (27%).
This report illustrates the typical weather in Sunnyside 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 Sunnyside.
For each station, the records are corrected for the elevation difference between that station and Sunnyside 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 Sunnyside is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Sunnyside and a given station.
The stations contributing to this reconstruction are: Hanford (43%, 41 kilometers, northeast); Yakima Air Terminal Airport (32%, 49 kilometers, northwest); Hermiston Municipal Airport (16%, 80 kilometers, southeast); and The Dalles Municipal Airport (9%, 119 kilometers, southwest).
Time zones for aiports and weather stations are provided by AskGeo.com .