Silverton, OR 97381 Frost Dates
Silverton, OR: when does the frost end?
Typically, the last spring freeze lands around 04/03, roughly 218 days out. Fall's first freeze usually shows up around 11/01, roughly 212 days after the last spring frost.
Silverton 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 9 weeks until Silverton's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
04/03 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/10 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/27 and only about 1 year in 10 sees frost after that.
Silverton against the rest of the dataset
Silverton's growing season runs about 212 days, ranking 14,587 of 40,283 US ZIP codes measured here, longest to shortest. Within OR, it ranks 202 of 463.
Learn more
Before leaning on 97381's figures: zone vs. frost date explains why Zone 8b and Silverton's frost date answer different questions, while the frost range explains how to read the range around Silverton's dates instead of trusting one.