Frost Dates in Washington

At the middle station of the 110 in Washington where a freeze comes every year, the last spring frost (50%) is April 18 and the first fall frost October 23, a freeze-free season of 189 days. The last frost is earliest at Eastsound (Olga 2 SE, WA, February 26) and latest at Davenport (Davenport, WA, June 6), 100 days apart. The season runs from 94 days at Cheney to 276 at Eastsound.

96 of these stations were also in NOAA's previous normals, for 1981–2010. Between the two, the median station's freeze-free season grew 3 days longer, with the last spring frost 2 days earlier and the first fall frost 2 days later; the season lengthened at 56 stations and shortened at 34. The two periods share twenty years, so the change reflects mostly 2011–2020 against 1981–1990.