Half Moon Bay, CA 94038 Frost Dates
Frost dates for Half Moon Bay, CA, ZIP 94038
Around 01/11 is the usual last spring frost, about 136 days away. The first fall frost typically arrives around 01/10, about 365 frost-free days later.
Half Moon Bay sits in USDA Zone 10a (30 to 35°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 10a around Half Moon Bay has about 19 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 Half Moon Bay's last frost
01/11 is the middle of 30 years of NOAA records, not a promise. Plant by 02/12 and you're betting against frost in roughly 9 years out of 10. 12/23 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Half Moon Bay compares
About 365 days separate Half Moon Bay's last and first frost, putting it 1,710 of 40,283 ZIP codes nationally. Within CA, it ranks 832 of 2,555.
Learn more
the frost range explains how to read the range around Half Moon Bay's dates instead of trusting one, and local microclimates explains what one yard in Half Moon Bay can differ from the 94038 normal.