FrostDateCheck

Mammoth Lakes, CA 93529 Frost Dates

When can you plant in Mammoth Lakes, CA?

Zone 6a

Around 06/10 is the usual last spring frost, about 286 days away. The first fall frost typically arrives around 09/17, about 98 frost-free days later.

The USDA Plant Hardiness Zone Map puts Mammoth Lakes in Zone 6a (-10 to -5°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 3 weeks of growing season left in Mammoth Lakes before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

Why 06/10 isn't a guarantee

06/10 is the middle of 30 years of NOAA records, not a promise. Plant by 05/29 and you're betting against frost in roughly 9 years out of 10. 06/30 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Mammoth Lakes compares

About 98 days separate Mammoth Lakes's last and first frost, putting it 39,752 of 40,283 ZIP codes nationally. Within CA, it ranks 2,524 of 2,555.

Learn more

local microclimates covers what one yard in Mammoth Lakes can differ from the 93529 normal. zone vs. frost date covers why Zone 6a and Mammoth Lakes's frost date answer different questions.