Summer 2023 bears the distinction as being the fifth-hottest summer since the National Weather Service in Spokane began tracking temperatures in 1881.
The summertime season, defined in meteorological terms as June 1 through Aug. 31, had a mean temperature (combining the daytime highs and overnight lows) of 71.1 degrees, compared to the historical average of 67.2 degrees. No single scorching event lifted summer 2023 to No. 5 on the heat-o-meter. Instead, June, July and August each ran about 4 degrees warmer than normal.
The city’s highest temperature this summer was 102 degrees on Aug. 15, followed by 101 degrees on Aug. 16. The warmest overnight low was 69 degrees on Aug. 17. Other toasty highs include 91 degrees on June 7, which is unusually warm for early summer, and 97 degrees on July 9, 16 and 20.
It’s interesting to note that four out of Spokane’s five’s warmest summers occurred within the past eight years. The hottest summer on record is 2021, when the average temperature was 73.1 degrees and Spokane registered its highest temperature ever recorded – 109 degrees at Spokane International Airport on June 29. The area’s second hottest summer was in 2015, the third in 1922, the fourth in 2017 and now the fifth in 2023.
The main trigger of our recent summer’s heat was a persistent high pressure system known as a heat dome that pushed hot, sinking air directly into the region. Instead of weakening and drifting away, the atmospheric pattern would wane, only to build back up.
The month of May was likely a contributing factor to the unusual stretch of summer warmth. Eight degrees above the historical average, May 2023 was the hottest May ever recorded in the Spokane area. Daily high temperature records toppled, including 85 degrees on May 2-3, which was so extreme that tulips wilted in the early-season heat.
Summer ran hot and also dry. The season’s rainfall total was 1.96 inches, compared to the average total of 2.36 inches. The heaviest rainfall was 0.39 inches on Aug. 22. Before then, the last measurable rainfall was 0.12 inches on July 10. No severe thunderstorms struck. Just some occasional rumbles, lightning flashes and an unsubstantial amount of raindrops.
Now that we’ve entered meteorological autumn, enjoyable summery weather is forecast this weekend, with mostly sunny skies and temperatures near 80 degrees.
Nic Loyd is a meteorologist in Washington state. Linda Weiford is a writer in Moscow, Idaho, who’s also a weather geek.