Claremont, CA 93563 Frost Dates
93563, near Claremont, CA: the frost window
Typically, the last spring freeze lands around 05/16, roughly 261 days out. Fall's first freeze usually shows up around 10/13, roughly 151 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Claremont in Zone 8a (10 to 15°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
Claremont's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
05/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/25 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/09 and only about 1 year in 10 sees frost after that.
Claremont against the rest of the dataset
At roughly 151 frost-free days, Claremont places 34,943 of 40,283 ZIP codes in this dataset. Within CA, it ranks 2,433 of 2,555.
Learn more
Two guides worth reading on 93563: zone vs. frost date, on why Zone 8a and Claremont's frost date answer different questions, and the frost range, on how to read the range around Claremont's dates instead of trusting one.