Healdsburg, CA 95471 Frost Dates
Healdsburg, CA: when does the frost end?
Typically, the last spring freeze lands around 03/20, roughly 204 days out. Fall's first freeze usually shows up around 11/13, roughly 240 days after the last spring frost.
Healdsburg 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.
Stretching the season past the first frost
With roughly 11 weeks until Healdsburg's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 03/20 isn't a guarantee
03/20 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/12 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/19 and only about 1 year in 10 sees frost after that.
Healdsburg against the rest of the dataset
Healdsburg's growing season runs about 240 days, ranking 8,677 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 2,121 of 2,555.
Learn more
Before leaning on 95471's figures: local microclimates explains what one yard in Healdsburg can differ from the 95471 normal, while zone vs. frost date explains why Zone 9b and Healdsburg's frost date answer different questions.