Wilsonville, OR 97070 Frost Dates
Frost dates for Wilsonville, OR, ZIP 97070
Around 03/16 is the usual last spring frost, about 200 days away. The first fall frost typically arrives around 11/14, about 242 frost-free days later.
The USDA Plant Hardiness Zone Map puts Wilsonville in Zone 8b (15 to 20°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
Zone 8b around Wilsonville has about 11 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 03/16 isn't a guarantee
03/16 is the middle of 30 years of NOAA records, not a promise. Plant by 02/21 and you're betting against frost in roughly 9 years out of 10. 04/07 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Wilsonville compares
At roughly 242 frost-free days, Wilsonville places 8,350 of 40,283 ZIP codes in this dataset. Within OR, it ranks 109 of 463.
Learn more
the frost range explains how to read the range around Wilsonville's dates instead of trusting one, and local microclimates explains what one yard in Wilsonville can differ from the 97070 normal.