Ukiah, OR 97880 Frost Dates
97880, near Ukiah, OR: the frost window
Typically, the last spring freeze lands around 06/05, roughly 281 days out. Fall's first freeze usually shows up around 09/14, roughly 99 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Ukiah in Zone 6b (-5 to 0°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Ukiah's growing season runs out in roughly 2 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 06/05 isn't a guarantee
06/05 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/16 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/25 and only about 1 year in 10 sees frost after that.
Ukiah against the rest of the dataset
At roughly 99 frost-free days, Ukiah places 39,740 of 40,283 ZIP codes in this dataset. Within OR, it ranks 415 of 463.
Learn more
Two guides worth reading on 97880: zone vs. frost date, on why Zone 6b and Ukiah's frost date answer different questions, and the frost range, on how to read the range around Ukiah's dates instead of trusting one.