Fossil, OR 97830 Frost Dates
When can you plant in Fossil, OR?
Around 06/03 is the usual last spring frost, about 279 days away. The first fall frost typically arrives around 09/14, about 98 frost-free days later.
The USDA Plant Hardiness Zone Map puts Fossil 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 2 weeks of growing season left in Fossil before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Fossil's last frost
06/03 is the middle of 30 years of NOAA records, not a promise. Plant by 05/13 and you're betting against frost in roughly 9 years out of 10. 07/03 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Fossil compares
At roughly 98 frost-free days, Fossil places 39,762 of 40,283 ZIP codes in this dataset. Within OR, it ranks 424 of 463.
Learn more
local microclimates covers what one yard in Fossil can differ from the 97830 normal. zone vs. frost date covers why Zone 7a and Fossil's frost date answer different questions.