Tillamook, OR 97143 Frost Dates
97143, near Tillamook, OR: the frost window
Typically, the last spring freeze lands around 03/17, roughly 201 days out. Fall's first freeze usually shows up around 11/22, roughly 251 days after the last spring frost.
Tillamook sits in USDA Zone 9a (20 to 25°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
Tillamook's growing season runs out in roughly 12 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 03/17 isn't a guarantee
03/17 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/09 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/15 and only about 1 year in 10 sees frost after that.
Tillamook against the rest of the dataset
Tillamook's growing season runs about 251 days, ranking 7,326 of 40,283 US ZIP codes measured here, longest to shortest. Within OR, it ranks 59 of 463.
Learn more
Two guides worth reading on 97143: local microclimates, on what one yard in Tillamook can differ from the 97143 normal, and zone vs. frost date, on why Zone 9a and Tillamook's frost date answer different questions.