Rio Dell, CA 95571 Frost Dates
95571, near Rio Dell, CA: the frost window
The last spring frost here typically falls around 03/04, about 188 days from today. Fall's first freeze usually shows up around 11/22, roughly 264 days after the last spring frost.
Rio Dell 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
Rio Dell's growing season runs out in roughly 12 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Rio Dell's last frost
03/04 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/27 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/08 and only about 1 year in 10 sees frost after that.
Rio Dell against the rest of the dataset
At roughly 264 frost-free days, Rio Dell places 6,071 of 40,283 ZIP codes in this dataset. Within CA, it ranks 2,012 of 2,555.
Learn more
Two guides worth reading on 95571: local microclimates, on what one yard in Rio Dell can differ from the 95571 normal, and zone vs. frost date, on why Zone 9b and Rio Dell's frost date answer different questions.