Grass Valley, CA 95946 Frost Dates
Grass Valley, CA: when does the frost end?
Typically, the last spring freeze lands around 04/10, roughly 225 days out. Fall's first freeze usually shows up around 11/13, roughly 215 days after the last spring frost.
Grass Valley sits in USDA Zone 9b (25 to 30°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 11 weeks until Grass Valley'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
04/10 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/17 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/30 and only about 1 year in 10 sees frost after that.
Grass Valley against the rest of the dataset
About 215 days separate Grass Valley's last and first frost, putting it 14,048 of 40,283 ZIP codes nationally. Within CA, it ranks 2,187 of 2,555.
Learn more
Before leaning on 95946's figures: zone vs. frost date explains why Zone 9b and Grass Valley's frost date answer different questions, while the frost range explains how to read the range around Grass Valley's dates instead of trusting one.