Rio Dell, CA 95514 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.
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.
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.
How much risk comes with planting early here
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
Rio Dell's growing season runs about 264 days, ranking 6,062 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 2,003 of 2,555.
Learn more
local microclimates covers what one yard in Rio Dell can differ from the 95514 normal. zone vs. frost date covers why Zone 9a and Rio Dell's frost date answer different questions.