August turned in the hottest temperature in Washington since 1991, and the June-August period for the state was the second warmest ever, according to Nic Loyd, Washington State University ag meteorologist.
"Low temperatures in August were the warmest on record as a result of that month's humid and periodically cloudy conditions," reports the WSU AgWeatherNet researcher. "In a broader context, however, this summer is just the latest noteworthy episode in a continuing warm period that has persisted in central Washington for year and a half."
As fall settled in, days in the field were numbered by heavier rainfall. In Whitman County, for example, the National Agricultural Statistics Service reports only 3.5 days were suitable for field work in the final week of September. Planting of winter wheat was stalled by cool, wet conditions.
Yakima Valley, temperatures as low as 33 degrees caused some fruit producers to use frost control measures.
Summer of 2013 marks the sixth season in a row of warmer than average temperature for Washington, notes Loyd. A 2.1 degree rise in normal summer temperatures for the state makes this the most significantly above-normal season in more than a decade, he adds.
While August began with relatively cool and unsettled weather in Washington, rain-cooled high temperature was only 59 degrees near Spokane on Aug. 2. But temperatures quickly rose again to reach 100 degrees near Paterson four days later. Most of the month was hot and somewhat humid, as periodic impulses spawned several thunderstorm episodes.
An Aug. 1 torrential storm resulted in a .63 inch downpour in Wenatchee, although nearby hardly any rainfall occurred.
At summer's end, western Washington received its first widespread rainfall in two months on Aug. 28 and 29.
Numerous wildfires resulted from the summer's scorching heat.
Other summer weather highlights include a .75-inch rainfall at Prosser on June 18, and a daily high of only 49 degrees in Green Bluff on June 30.