Plymouth, CA 95669 Frost Dates
95669, near Plymouth, CA: the frost window
Around 03/31 is the usual last spring frost, about 215 days away. Fall's first freeze usually shows up around 11/21, roughly 237 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Plymouth 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
Plymouth's growing season runs out in roughly 12 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
03/31 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/24 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/23 and only about 1 year in 10 sees frost after that.
Plymouth against the rest of the dataset
At roughly 237 frost-free days, Plymouth places 9,133 of 40,283 ZIP codes in this dataset. Within CA, it ranks 2,141 of 2,555.
Learn more
Two guides worth reading on 95669: the frost range, on how to read the range around Plymouth's dates instead of trusting one, and local microclimates, on what one yard in Plymouth can differ from the 95669 normal.