Union City, CA 94555 Frost Dates
Union City, CA: when does the frost end?
The last spring frost here typically falls around 01/07, about 132 days from today. Fall's first freeze usually shows up around 12/22, roughly 353 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 Union City, not a forecast for this year.
Stretching the season past the first frost
With roughly 17 weeks until Union City's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
01/07 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/07 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.
Union City against the rest of the dataset
At roughly 353 frost-free days, Union City places 2,217 of 40,283 ZIP codes in this dataset. Within CA, it ranks 997 of 2,555.
Learn more
Before leaning on 94555's figures: zone vs. frost date explains why Zone 10a and Union City's frost date answer different questions, while the frost range explains how to read the range around Union City's dates instead of trusting one.