What plant hardiness zone is Union City

Union City is located at Alameda County, California (CA), USA.

Plant hardiness zone (winter frost zone or gardening zone) for Union City is 10a by the USDA scale.

Coldest zone's winter temperature is +30 … +35 °F.

Plants of 10a USDA hardiness zone suitable for outdoor gardening and growing in this winter frost zone 10a USDA.

Union City, California @ wikipedia.