Grass Valley, OR 97029 Frost Dates
When can you plant in Grass Valley, OR?
Typically, the last spring freeze lands around 05/15, roughly 260 days out. The first fall frost typically arrives around 10/11, about 147 frost-free days later.
The USDA Plant Hardiness Zone Map puts Grass Valley in Zone 7a (0 to 5°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 6 weeks of growing season left in Grass Valley 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
05/15 is the middle of 30 years of NOAA records, not a promise. Plant by 04/29 and you're betting against frost in roughly 9 years out of 10. 06/06 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Grass Valley compares
About 147 days separate Grass Valley's last and first frost, putting it 35,989 of 40,283 ZIP codes nationally. Within OR, it ranks 354 of 463.
Learn more
zone vs. frost date covers why Zone 7a and Grass Valley's frost date answer different questions. the frost range covers how to read the range around Grass Valley's dates instead of trusting one.