Mammoth Lakes, CA 93541 Frost Dates
Frost dates for Mammoth Lakes, CA, ZIP 93541
Typically, the last spring freeze lands around 05/23, roughly 268 days out. The first fall frost typically arrives around 10/09, about 139 frost-free days later.
Mammoth Lakes sits in USDA Zone 6b (-5 to 0°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.
What to do before the first frost
Zone 6b around Mammoth Lakes has about 6 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
The actual range around Mammoth Lakes's last frost
05/23 is the middle of 30 years of NOAA records, not a promise. Plant by 05/02 and you're betting against frost in roughly 9 years out of 10. 06/09 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Mammoth Lakes compares
At roughly 139 frost-free days, Mammoth Lakes places 37,222 of 40,283 ZIP codes in this dataset. Within CA, it ranks 2,445 of 2,555.
Learn more
local microclimates explains what one yard in Mammoth Lakes can differ from the 93541 normal, and zone vs. frost date explains why Zone 6b and Mammoth Lakes's frost date answer different questions.