Average Weather in Union Gap Washington, United States
In Union Gap, the summers are hot, dry, and mostly clear and the winters are short, chilly, and partly cloudy. Over the course of the year, the temperature typically varies from 23°F to 91°F and is rarely below 10°F or above 100°F.
The hot season lasts for 3.1 months, from June 11 to September 14, with an average daily high temperature above 79°F. The hottest day of the year is July 30, with an average high of 91°F and low of 58°F.
The cold season lasts for 2.8 months, from November 19 to February 14, with an average daily high temperature below 47°F. The coldest day of the year is December 23, with an average low of 23°F and high of 36°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, 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 Union Gap, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in Union Gap begins around June 7 and lasts for 4.1 months, ending around October 9. On August 3, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 82% of the time, and overcast or mostly cloudy 18% of the time.
The cloudier part of the year begins around October 9 and lasts for 7.9 months, ending around June 7. On January 16, the cloudiest day of the year, the sky is overcast or mostly cloudy 65% of the time, and clear, mostly clear, or partly cloudy 35% of the time.
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Union Gap varies significantly throughout the year.
The wetter season lasts 5.3 months, from October 21 to March 30, with a greater than 19% chance of a given day being a wet day. The chance of a wet day peaks at 35% on November 28.
The drier season lasts 6.7 months, from March 30 to October 21. The smallest chance of a wet day is 3% on August 16.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation in Union Gap changes throughout the year.
Rain alone is the most common for 12 months, from January 4 to December 22. The highest chance of a day with rain alone is 29% on November 10.
Snow alone is the most common for 1.9 weeks, from December 22 to January 4. The highest chance of a day with snow alone is 12% on December 28.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Union Gap experiences some seasonal variation in monthly rainfall.
The rainy period of the year lasts for 8.7 months, from September 23 to June 15, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around November 20, with an average total accumulation of 2.0 inches.
The rainless period of the year lasts for 3.3 months, from June 15 to September 23. The least rain falls around August 5, with an average total accumulation of 0.2 inches.
Average Monthly Rainfall
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. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Union Gap experiences some seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 4.1 months, from November 4 to March 8, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around December 30, with an average total liquid-equivalent accumulation of 0.9 inches.
The snowless period of the year lasts for 7.9 months, from March 8 to November 4. The least snow falls around July 5, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Union Gap varies significantly over the course of the year. In 2017, the shortest day is December 21, with 8 hours, 34 minutes of daylight; the longest day is June 21, with 15 hours, 50 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:08 AM on June 15, and the latest sunrise is 2 hours, 40 minutes later at 7:48 AM on November 4. The earliest sunset is at 4:14 PM on December 10, and the latest sunset is 4 hours, 45 minutes later at 8:59 PM on June 25.
Daylight saving time (DST) is observed in Union Gap during 2017, starting in the spring on March 12, lasting 7.8 months, and ending in the fall on November 5.
Sunrise & Sunset with Twilight and Daylight Saving Time
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
The perceived humidity level in Union Gap, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.
Humidity Comfort Levels
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.The average hourly wind speed in Union Gap does not vary significantly over the course of the year, remaining within 0.4 miles per hour of 3.6 miles per hour throughout.
Average Wind Speed
The predominant average hourly wind direction in Union Gap varies throughout the year.
The wind is most often from the west for 1.4 weeks, from January 13 to January 23 and for 10 months, from February 2 to December 15, with a peak percentage of 69% on June 23. The wind is most often from the north for 1.4 weeks, from January 23 to February 2 and for 4.1 weeks, from December 15 to January 13, with a peak percentage of 39% on January 27.
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 3.3 months, from May 13 to August 21, with an average daily incident shortwave energy per square meter above 6.5 kWh. The brightest day of the year is July 13, with an average of 7.8 kWh.
The darker period of the year lasts for 3.7 months, from October 26 to February 18, with an average daily incident shortwave energy per square meter below 2.6 kWh. The darkest day of the year is December 26, with an average of 1.2 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Union Gap are 46.557 deg latitude, -120.475 deg longitude, and 1,017 ft elevation.
The topography within 2 miles of Union Gap contains very significant variations in elevation, with a maximum elevation change of 869 feet and an average elevation above sea level of 1,014 feet. Within 10 miles contains very significant variations in elevation (2,441 feet). Within 50 miles contains large variations in elevation (7,756 feet).
The area within 2 miles of Union Gap is covered by artificial surfaces (42%), cropland (30%), and shrubs (27%), within 10 miles by cropland (40%) and shrubs (40%), and within 50 miles by shrubs (59%) and trees (19%).
This report illustrates the typical weather in Union Gap, 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 2 weather stations near enough to contribute to our estimation of the temperature and dew point in Union Gap.
For each station, the records are corrected for the elevation difference between that station and Union Gap 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 Union Gap is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Union Gap and a given station.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.