Morgan Hill, CA 95158 Frost Dates
Frost dates for Morgan Hill, CA, ZIP 95158
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.
Morgan Hill sits in USDA Zone 9b (25 to 30°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 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.
Why 05/03 isn't a guarantee
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
At roughly 197 frost-free days, Morgan Hill places 18,610 of 40,283 ZIP codes in this dataset. Within CA, it ranks 2,282 of 2,555.
Learn more
zone vs. frost date explains why Zone 9b and Morgan Hill's frost date answer different questions, and the frost range explains how to read the range around Morgan Hill's dates instead of trusting one.