Rio Dell, CA 95552 Frost Dates
Frost dates for Rio Dell, CA, ZIP 95552
The last spring frost here typically falls around 04/16, about 231 days from today. The first fall frost typically arrives around 10/31, about 197 frost-free days later.
Rio Dell sits in USDA Zone 8b (15 to 20°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.
What to do before the first frost
Zone 8b around Rio Dell has about 9 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
Why 04/16 isn't a guarantee
04/16 is the middle of 30 years of NOAA records, not a promise. Plant by 03/23 and you're betting against frost in roughly 9 years out of 10. 05/03 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Rio Dell compares
About 197 days separate Rio Dell's last and first frost, putting it 18,684 of 40,283 ZIP codes nationally. Within CA, it ranks 2,295 of 2,555.
Learn more
zone vs. frost date explains why Zone 8b and Rio Dell's frost date answer different questions, and the frost range explains how to read the range around Rio Dell's dates instead of trusting one.