Williams, CA 95937 Frost Dates
Williams, CA: when does the frost end?
Typically, the last spring freeze lands around 02/14, roughly 170 days out. Fall's first freeze usually shows up around 12/01, roughly 293 days after the last spring frost.
Zone 9b (25 to 30°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Williams, not a forecast for this year.
Stretching the season past the first frost
With roughly 14 weeks until Williams's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 02/14 isn't a guarantee
02/14 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/02 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 03/31 and only about 1 year in 10 sees frost after that.
Williams against the rest of the dataset
At roughly 293 frost-free days, Williams places 4,291 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,667 of 2,555.
Learn more
Before leaning on 95937's figures: the frost range explains how to read the range around Williams's dates instead of trusting one, while local microclimates explains what one yard in Williams can differ from the 95937 normal.