Warmest spring in 20 years ends with hottest May since 1997

By Rachel Webber, College of Agricultural, Human & Natural Resource Sciences

agweathernet-logo-250PROSSER, Wash. – Turnabout is fair play and, apparently, the weather agrees. In a span of three years, Washingtonians have experienced both extremes of spring weather.

In 2011, the state lived through one of the coolest early growing seasons on record, only to see one of the warmest in recent memory in 2014.

“Prosser’s mean spring high temperature this year was about two degrees above average and more than five degrees warmer than 2011,” said AgWeatherNet meteorologist Nic Loyd.

A Web-based, publicly available system, AgWeatherNet (http://weather.wsu.edu/awn.php) provides access to near real-time weather data and value-added products from Washington State University’s statewide weather network, along with decision aids for agricultural producers and other users.

Cool start was short-lived

The temperature difference was particularly striking in May, Loyd said: “Prosser’s mean May high temperature was eight degrees warmer in 2014 than in 2011. Despite their modest appearance, these values are indeed significant on monthly and especially seasonal time scales.”

Contrary to the predominantly warm recent conditions, the spring season commenced with a very brief period of unusually cool weather. The high temperature at Green Bluff on March 1 was 19 degrees during a late season cold outbreak.

However, Vancouver rose to 62 degrees two days later.

Most notably, Montesano recorded nearly 8 inches of rain during the week ending on March 8. An unfortunate consequence of the wet western weather was the devastating March 22 landslide near Oso.

Heat waves break record

A major heat wave at the end of April caused the high temperature at Long Beach to rise from 58 degrees on April 28 to 88 degrees on April 30. The sweltering reading shattered the previous April record by 12 degrees and marked the warmest temperature since September 2012.

On May 1, the heat spread eastward and Seattle spiked to 89 degrees. However, a return to onshore flow allowed the daily high to decrease to a more seasonable 69 degrees on May 2.

Several additional heat waves followed later in May, interspersed with somewhat cooler periods. Highs reached 89 degrees at Long Beach on May 14, as some areas of northwestern Oregon soared into the low 90s.

Temperatures fell to 30 degrees at Ritzville on May 27, but warmer conditions returned for the end of spring.

Minimal frost damage to crops

Other highlights of the season included 1.7 inches of rain at Stevenson on May 9 and 2.2 inches of rain at Stevenson on March 5.

“Washington growers were fortunate to escape the early part of the growing season with minimal frost damage,” said Gerrit Hoogenboom, AgWeatherNet director. “However, with summer upon us, our agricultural concerns have shifted from cold damage to heat and drought stress.”


Nic Loyd, WSU AgWeatherNet meteorologist, 509-786-9357, nicholas.loyd@wsu.edu

Rachel Webber, WSU College of Agricultural, Human and Natural Resource Sciences Communications, 509-335-0837, rcwebber@wsu.edu