Ione, CA 95640 Frost Dates
95640, near Ione, CA: the frost window
Around 01/22 is the usual last spring frost, about 147 days away. Fall's first freeze usually shows up around 12/17, roughly 332 days after the last spring frost.
Ione sits in USDA Zone 9b (25 to 30°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
Ione's growing season runs out in roughly 16 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 01/22 isn't a guarantee
01/22 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/01 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/23 and only about 1 year in 10 sees frost after that.
Ione against the rest of the dataset
Ione's growing season runs about 332 days, ranking 2,873 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,298 of 2,555.
Learn more
Two guides worth reading on 95640: zone vs. frost date, on why Zone 9b and Ione's frost date answer different questions, and the frost range, on how to read the range around Ione's dates instead of trusting one.