Rio Dell, CA 95542 Frost Dates
Rio Dell, CA: when does the frost end?
The last spring frost here typically falls around 03/10, about 194 days from today. Fall's first freeze usually shows up around 12/01, roughly 271 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Rio Dell in Zone 9a (20 to 25°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 14 weeks until Rio Dell's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 03/10 isn't a guarantee
03/10 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/09 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/13 and only about 1 year in 10 sees frost after that.
Rio Dell against the rest of the dataset
About 271 days separate Rio Dell's last and first frost, putting it 5,439 of 40,283 ZIP codes nationally. Within CA, it ranks 1,893 of 2,555.
Learn more
Before leaning on 95542's figures: the frost range explains how to read the range around Rio Dell's dates instead of trusting one, while local microclimates explains what one yard in Rio Dell can differ from the 95542 normal.