Morgan Hill, CA 94023 Frost Dates
Frost dates for Morgan Hill, CA, ZIP 94023
Typically, the last spring freeze lands around 05/03, roughly 248 days out. The first fall frost typically arrives around 11/18, about 197 frost-free days later.
The USDA Plant Hardiness Zone Map puts Morgan Hill in Zone 9b (25 to 30°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
Zone 9b around Morgan Hill has about 12 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.
How much risk comes with planting early here
05/03 is the middle of 30 years of NOAA records, not a promise. Plant by 04/07 and you're betting against frost in roughly 9 years out of 10. 06/05 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Morgan Hill compares
About 197 days separate Morgan Hill's last and first frost, putting it 18,578 of 40,283 ZIP codes nationally. Within CA, it ranks 2,250 of 2,555.
Learn more
local microclimates explains what one yard in Morgan Hill can differ from the 94023 normal, and zone vs. frost date explains why Zone 9b and Morgan Hill's frost date answer different questions.