Hidden Hills, CA 91316 Frost Dates
91316, near Hidden Hills, CA: the frost window
The last spring frost here typically falls around 12/31, about 125 days from today. Fall's first freeze usually shows up around 12/30, roughly 365 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 Hidden Hills, not a forecast for this year.
Stretching the season past the first frost
Hidden Hills's growing season runs out in roughly 18 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 12/31 isn't a guarantee
12/31 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 01/27 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/09 and only about 1 year in 10 sees frost after that.
Hidden Hills against the rest of the dataset
About 365 days separate Hidden Hills's last and first frost, putting it 1,962 of 40,283 ZIP codes nationally. Within CA, it ranks 894 of 2,555.
Learn more
Two guides worth reading on 91316: zone vs. frost date, on why Zone 10a and Hidden Hills's frost date answer different questions, and the frost range, on how to read the range around Hidden Hills's dates instead of trusting one.