Plymouth, CA 95675 Frost Dates
When can you plant in Plymouth, CA?
Typically, the last spring freeze lands around 03/31, roughly 215 days out. The first fall frost typically arrives around 11/21, about 237 frost-free days later.
The USDA Plant Hardiness Zone Map puts Plymouth in Zone 9a (20 to 25°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 12 weeks of growing season left in Plymouth before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 03/31 isn't a guarantee
03/31 is the middle of 30 years of NOAA records, not a promise. Plant by 02/24 and you're betting against frost in roughly 9 years out of 10. 04/23 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Plymouth compares
Plymouth's growing season runs about 237 days, ranking 9,134 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 2,142 of 2,555.
Learn more
local microclimates covers what one yard in Plymouth can differ from the 95675 normal. zone vs. frost date covers why Zone 9a and Plymouth's frost date answer different questions.