Yountville, CA 94599 Frost Dates
94599, near Yountville, CA: the frost window
Typically, the last spring freeze lands around 03/02, roughly 186 days out. Fall's first freeze usually shows up around 11/27, roughly 270 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Yountville in Zone 9b (25 to 30°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
Yountville's growing season runs out in roughly 13 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
03/02 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/27 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/05 and only about 1 year in 10 sees frost after that.
Yountville against the rest of the dataset
At roughly 270 frost-free days, Yountville places 5,577 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,979 of 2,555.
Learn more
Two guides worth reading on 94599: local microclimates, on what one yard in Yountville can differ from the 94599 normal, and zone vs. frost date, on why Zone 9b and Yountville's frost date answer different questions.