Atherton, CA 94063 Frost Dates
94063, near Atherton, CA: the frost window
Around 01/17 is the usual last spring frost, about 142 days away. Fall's first freeze usually shows up around 12/12, roughly 333 days after the last spring frost.
Zone 10a (30 to 35°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Atherton, not a forecast for this year.
Stretching the season past the first frost
Atherton's growing season runs out in roughly 15 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Atherton's last frost
01/17 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/16 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/20 and only about 1 year in 10 sees frost after that.
Atherton against the rest of the dataset
At roughly 333 frost-free days, Atherton places 2,848 of 40,283 ZIP codes in this dataset. Within CA, it ranks 1,294 of 2,555.
Learn more
Two guides worth reading on 94063: the frost range, on how to read the range around Atherton's dates instead of trusting one, and local microclimates, on what one yard in Atherton can differ from the 94063 normal.