Healdsburg, CA 95421 Frost Dates
Frost dates for Healdsburg, CA, ZIP 95421
Around 01/29 is the usual last spring frost, about 154 days away. The first fall frost typically arrives around 12/30, about 347 frost-free days later.
Zone 9b (25 to 30°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Healdsburg, not a forecast for this year.
What to do before the first frost
Zone 9b around Healdsburg has about 18 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 Healdsburg's last frost
01/29 is the middle of 30 years of NOAA records, not a promise. Plant by 03/17 and you're betting against frost in roughly 9 years out of 10. 12/17 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Healdsburg compares
About 347 days separate Healdsburg's last and first frost, putting it 2,398 of 40,283 ZIP codes nationally. Within CA, it ranks 1,085 of 2,555.
Learn more
local microclimates explains what one yard in Healdsburg can differ from the 95421 normal, and zone vs. frost date explains why Zone 9b and Healdsburg's frost date answer different questions.