Pullman, WA 99163 Frost Dates
Pullman, WA: when does the frost end?
Typically, the last spring freeze lands around 04/29, roughly 244 days out. Fall's first freeze usually shows up around 10/02, roughly 159 days after the last spring frost.
Pullman sits in USDA Zone 6b (-5 to 0°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
With roughly 5 weeks until Pullman's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Pullman's last frost
04/29 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/07 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/14 and only about 1 year in 10 sees frost after that.
Pullman against the rest of the dataset
At roughly 159 frost-free days, Pullman places 32,585 of 40,283 ZIP codes in this dataset. Within WA, it ranks 574 of 700.
Learn more
Before leaning on 99163's figures: zone vs. frost date explains why Zone 6b and Pullman's frost date answer different questions, while the frost range explains how to read the range around Pullman's dates instead of trusting one.