Union City, CA 94587 Frost Dates
When can you plant in Union City, CA?
Typically, the last spring freeze lands around 01/07, roughly 132 days out. The first fall frost typically arrives around 12/22, about 353 frost-free days later.
Union City sits in USDA Zone 10a (30 to 35°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.
What to do before the first frost
About 17 weeks of growing season left in Union City before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Union City's last frost
01/07 is the middle of 30 years of NOAA records, not a promise. Plant by 02/07 and you're betting against frost in roughly 9 years out of 10. 12/14 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Union City compares
At roughly 353 frost-free days, Union City places 2,218 of 40,283 ZIP codes in this dataset. Within CA, it ranks 998 of 2,555.
Learn more
the frost range covers how to read the range around Union City's dates instead of trusting one. local microclimates covers what one yard in Union City can differ from the 94587 normal.