Rio Dell, CA 95553 Frost Dates
95553, near Rio Dell, CA: the frost window
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 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 14 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
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 5,440 of 40,283 ZIP codes nationally. Within CA, it ranks 1,894 of 2,555.
Learn more
Two guides worth reading on 95553: zone vs. frost date, on why Zone 9b and Rio Dell's frost date answer different questions, and the frost range, on how to read the range around Rio Dell's dates instead of trusting one.