PROSSER, Wash. — From record heat to record cold and everything in between, the Washington 2011 weather year had it all. “Despite the unusual weather in Washington last year, it can be understood more easily by thinking of 2011 as a year in which the seasons were delayed by one month,” said Washington State University AgWeatherNet meteorologist Nic Loyd. “Cool and spring-like conditions continued into July, while the warmest temperatures of the year were pushed back until early September. August was the warmest month of 2011, instead of July, and September was five degrees warmer than June, even though June is typically the warmer month.”
Temperatures rose into the 60s at times in mid January and again in mid February of 2011. However, a late-season arctic blast sent temperatures tumbling into the single digits in central Washington on the morning of February 26. This unusual event heralded the beginning of what was to be the coolest and windiest spring in recent memory in central Washington. “Despite the delayed crops that resulted from the below normal springtime temperatures, there were benefits as well,” said Gerrit Hoogenboom, director of AgWeatherNet. “The mountain snowpack increased throughout the spring, which led to an abundant summer water supply.”
Cool conditions continued into July, and normal summertime heat was not observed until August. Summer finally arrived in September, with near record heat in many locations. Areas north of Wenatchee surpassed 100 degrees as late as Sept. 12, while Prosser recorded high temperatures above 90 degrees for five consecutive days from Sept. 9 to 13. The first autumn frost in the normally cold locations of central Washington came late, allowing for a safe harvest of a delayed apple crop. December featured unusually quiet weather with almost no precipitation in Washington until Christmas. Heavy rain during the last week of the year saved western Washington from experiencing the driest December on record, although rainfall was still well below normal for the month. All in all, 2011 ended just as it had begun: with very unusual weather.
Temperatures in Washington were generally below average in 2011. The 2011 average temperature at WSU Prosser was one degree below average at 50.7 degrees. And both the high and low temperatures were cooler than average. Despite the cool conditions, 2011 was far from a record year. For the period of record (1990 to 2011), 1993 was the coolest year, with an average temperature of 49.4 degrees.
A more detailed review of Washington’s 2011 weather is available at the AgWeatherNet website, www.weather.wsu.edu, 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.