Happy Valley, OR 97015 Frost Dates
Happy Valley, OR: when does the frost end?
Around 03/16 is the usual last spring frost, about 200 days away. Fall's first freeze usually shows up around 11/20, roughly 250 days after the last spring frost.
Zone 9a (20 to 25°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Happy Valley, not a forecast for this year.
Stretching the season past the first frost
With roughly 12 weeks until Happy Valley's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Happy Valley's last frost
03/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/18 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/12 and only about 1 year in 10 sees frost after that.
Happy Valley against the rest of the dataset
At roughly 250 frost-free days, Happy Valley places 7,460 of 40,283 ZIP codes in this dataset. Within OR, it ranks 66 of 463.
Learn more
Before leaning on 97015's figures: the frost range explains how to read the range around Happy Valley's dates instead of trusting one, while local microclimates explains what one yard in Happy Valley can differ from the 97015 normal.