Forest Grove, OR 97076 Frost Dates
Forest Grove, OR: when does the frost end?
Typically, the last spring freeze lands around 04/16, roughly 231 days out. Fall's first freeze usually shows up around 10/26, roughly 192 days after the last spring frost.
Forest Grove sits in USDA Zone 8b (15 to 20°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.
Stretching the season past the first frost
With roughly 8 weeks until Forest Grove's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 04/16 isn't a guarantee
04/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/26 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/05 and only about 1 year in 10 sees frost after that.
Forest Grove against the rest of the dataset
About 192 days separate Forest Grove's last and first frost, putting it 20,179 of 40,283 ZIP codes nationally. Within OR, it ranks 265 of 463.
Learn more
Before leaning on 97076's figures: zone vs. frost date explains why Zone 8b and Forest Grove's frost date answer different questions, while the frost range explains how to read the range around Forest Grove's dates instead of trusting one.