Rio Dell, CA 95569 Frost Dates
When can you plant in Rio Dell, CA?
Around 03/04 is the usual last spring frost, about 188 days away. The first fall frost typically arrives around 11/22, about 264 frost-free days later.
The USDA Plant Hardiness Zone Map puts Rio Dell in Zone 9b (25 to 30°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 12 weeks of growing season left in Rio Dell before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 03/04 isn't a guarantee
03/04 is the middle of 30 years of NOAA records, not a promise. Plant by 01/27 and you're betting against frost in roughly 9 years out of 10. 04/08 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Rio Dell compares
About 264 days separate Rio Dell's last and first frost, putting it 6,070 of 40,283 ZIP codes nationally. Within CA, it ranks 2,011 of 2,555.
Learn more
the frost range covers how to read the range around Rio Dell's dates instead of trusting one. local microclimates covers what one yard in Rio Dell can differ from the 95569 normal.