Los Altos, CA 94024 Frost Dates
Los Altos, CA: when does the frost end?
Around 01/06 is the usual last spring frost, about 131 days away. Fall's first freeze usually shows up around 12/23, roughly 353 days after the last spring frost.
Los Altos 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
With roughly 17 weeks until Los Altos's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 01/06 isn't a guarantee
01/06 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/04 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/16 and only about 1 year in 10 sees frost after that.
Los Altos against the rest of the dataset
Los Altos's growing season runs about 353 days, ranking 2,226 of 40,283 US ZIP codes measured here, longest to shortest. Within CA, it ranks 1,002 of 2,555.
Learn more
Before leaning on 94024's figures: local microclimates explains what one yard in Los Altos can differ from the 94024 normal, while zone vs. frost date explains why Zone 9b and Los Altos's frost date answer different questions.