Pomona, CA 91768 Frost Dates
Pomona, CA: when does the frost end?
Around 01/08 is the usual last spring frost, about 133 days away. Fall's first freeze usually shows up around 12/28, roughly 354 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 Pomona, not a forecast for this year.
Stretching the season past the first frost
With roughly 17 weeks until Pomona's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 01/08 isn't a guarantee
01/08 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/18 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 12/14 and only about 1 year in 10 sees frost after that.
Pomona against the rest of the dataset
About 354 days separate Pomona's last and first frost, putting it 2,166 of 40,283 ZIP codes nationally. Within CA, it ranks 970 of 2,555.
Learn more
Before leaning on 91768's figures: local microclimates explains what one yard in Pomona can differ from the 91768 normal, while zone vs. frost date explains why Zone 10a and Pomona's frost date answer different questions.