Rio Dell, CA 95511 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.
Rio Dell sits in USDA Zone 9a (20 to 25°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 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
Rio Dell's growing season runs about 271 days, ranking 5,438 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,892 of 2,555.
Learn more
Before leaning on 95511's figures: local microclimates explains what one yard in Rio Dell can differ from the 95511 normal, while zone vs. frost date explains why Zone 9a and Rio Dell's frost date answer different questions.