PROSSER, Wash. – Don’t be fooled by the recent stretch of pleasant late-summer weather. Most of Washington’s 2012 summer weather featured conditions that ranged from bad to downright ugly. From the severe storms in mid-July to the raging wildfires and parching heat in August, a great diversity of weather concerns epitomized the summer season.
“Although events such as the severe weather outbreak of July 20 were very damaging to certain sectors of Washington agriculture, many growers managed to effectively weather the difficulties of the season,” said AgWeatherNet director Gerrit Hoogenboom. “Fortunately, many fields and orchards have good crop quality, and numerous harvests are producing normal yields.”
Each month of the season featured a unique character, thanks to a variety of weather events. “The story of Washington’s summer is one of feast and famine,” said AgWeatherNet meteorologist Nic Loyd. “June’s cool and wet weather stands in stark contrast to the hot and dry conditions observed in August. Although the overall summer temperatures were near average, there was a lot of action going on at any given time.”
Below normal temperatures and above normal rainfall characterized June, as daytime high temperatures were generally three degrees or more below average. Pullman reached only 48 degrees for a high on June 9, while Ritzville dropped to a frosty 31.7 degrees on the June 15. WSU’s research center in Prosser experienced its second wettest June on record, while a weather station in south-central Washington experienced an all-time daily record rainfall of nearly one and a half inches on June 4.
The weather warmed significantly during July, and was slightly above average for the month. However, the most notable feature of the month was the severe weather outbreak of July 20, which ended a week-long stretch of humid weather and daily thunderstorms. Some areas received three-quarters of an inch of rain in only 15 minutes. Isolated areas received devastating crop losses of near 100 percent due to hail damage. There was also a heat wave early in the month that sent temperatures soaring to as high as 107 degrees in central Washington. July 8 was a particularly interesting day that featured both extreme heat and thunderstorms. Parts of the Yakima Valley received over a quarter-inch of rain following afternoon highs in the 100s. Some areas experienced the hottest rainy day on record.
In August, dry weather dominated the state for the entire month, as fires and smoke-filled skies plagued the region. Many areas continue to experience dry streaks that have surpassed 50 days at the end of August, with little relief in sight. Although eastern Washington did not contend with unprecedented heat, temperatures were consistently very warm, with highs in the upper 80s to low 100s for several weeks. WSU Prosser set monthly records for the warmest daily low temperature (69.1˚F on August 15), and the warmest daily average temperature (83.8˚F on August 6). The first day with below average temperatures did not occur until the 22. Hot weather during early and mid August transitioned to more seasonal weather during the latter part of the month. Highs were generally in the 80s, while lows dropped into the 40s and 50s, as pleasantly warm days gave way to clear, cool nights.
“This year certainly reflects the recent trend of cool, wet conditions early in the summer transitioning to warm, dry conditions by later in the summer,” said Loyd.
For more information on Washington’s summer weather, as well as other weather information, please see the Summer Weather Review on the AgWeatherNet website, www.weather.wsu.edu, located under the News link. A Web based, publicly available system, AgWeatherNet provides access to near real-time weather data and value-added products from WSU’s statewide weather network, along with decision aids for agricultural producers and other users.