This report describes the typical weather at the Bowers Field (Ellensburg, Washington, United States) weather station over the course of an average year. It is based on the historical records from 1999 to 2012. Earlier records are either unavailable or unreliable.
Ellensburg, Washington has a cold semi-arid steppe climate. The area within 25 mi of this station is covered by forests (35%), shrublands (27%), grasslands (25%), and croplands (12%).
Over the course of a year, the temperature typically varies from 23°F to 87°F and is rarely below 12°F or above 96°F.
The warm season lasts from June 18 to September 14 with an average daily high temperature above 76°F. The hottest day of the year is July 30, with an average high of 87°F and low of 58°F.
The cold season lasts from November 18 to February 19 with an average daily high temperature below 44°F. The coldest day of the year is December 26, with an average low of 23°F and high of 33°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 8:29 hours of daylight; the longest day is June 20 with 15:54 hours of daylight.
The earliest sunrise is at 5:06am on June 14 and the latest sunset is at 9:02pm on June 26. The latest sunrise is at 7:49am on November 3 and the earliest sunset is at 4:12pm on December 9.
Daylight saving time (DST) is observed in this location during 2012, starting in the spring on March 11 and ending in the fall on November 4.
The median cloud cover ranges from 0% (clear) to 86% (mostly cloudy). The sky is cloudiest on December 30 and clearest on July 13. The clearer part of the year begins around February 24. The cloudier part of the year begins around November 13.
On July 13, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 93% of the time, and overcast or mostly cloudy 6% of the time.
On December 30, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 64% of the time, and clear or mostly clear 33% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around December 22, occurring in 54% of days. Precipitation is least likely around August 5, occurring in 11% of days.
Over the entire year, the most common forms of precipitation are light rain, light snow, and moderate rain.
Light rain is the most severe precipitation observed during 48% of those days with precipitation. It is most likely around April 6, when it is observed during 24% of all days.
Light snow is the most severe precipitation observed during 29% of those days with precipitation. It is most likely around December 22, when it is observed during 29% of all days.
Moderate rain is the most severe precipitation observed during 10% of those days with precipitation. It is most likely around April 23, when it is observed during 6% of all days.
During the warm season, which lasts from June 18 to September 14, there is a 15% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of light rain (67% of days with precipitation have at worst light rain), thunderstorms (20%), moderate rain (8%), and heavy rain (5%).
During the cold season, which lasts from November 18 to February 19, there is a 49% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of light snow (51% of days with precipitation have at worst light snow), light rain (28%), moderate snow (13%), and moderate rain (7%).
The likelihood of snow falling is highest around December 25, occurring in 38% of days. The season in which it is relatively likely for snow to fall spans from October 30 to March 22.
Either snow rarely accumulates at this location or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 24% (dry) to 91% (very humid) over the course of the year, rarely dropping below 14% (very dry) and reaching as high as 100% (very humid).
The air is driest around July 26, at which time the relative humidity drops below 29% (dry) three days out of four; it is most humid around December 25, exceeding 87% (very humid) three days out of four.
Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.
Over the course of a year, the dew point typically varies from 18°F (dry) to 54°F (very comfortable) and is rarely below 6°F (dry) or above 59°F (comfortable).
The time of the year between July 1 and August 31 is the most comfortable, with dew points that are neither too dry nor too muggy.
Over the course of the year typical wind speeds vary from 0 mph to 25 mph (calm to strong breeze), rarely exceeding 33 mph (high wind).
The highest average wind speed of 15 mph (moderate breeze) occurs around June 14, at which time the average daily maximum wind speed is 25 mph (strong breeze).
The lowest average wind speed of 4 mph (light breeze) occurs around December 25, at which time the average daily maximum wind speed is 8 mph (gentle breeze).