West Richland, WA 99354 Frost Dates
West Richland, WA: when does the frost end?
Typically, the last spring freeze lands around 04/06, roughly 221 days out. Fall's first freeze usually shows up around 10/24, roughly 200 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts West Richland in Zone 7b (5 to 10°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 8 weeks until West Richland's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
04/06 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/22 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/24 and only about 1 year in 10 sees frost after that.
West Richland against the rest of the dataset
At roughly 200 frost-free days, West Richland places 17,731 of 40,283 ZIP codes in this dataset. Within WA, it ranks 318 of 700.
Learn more
Before leaning on 99354's figures: local microclimates explains what one yard in West Richland can differ from the 99354 normal, while zone vs. frost date explains why Zone 7b and West Richland's frost date answer different questions.