Union City, California

Union City population, 2020 to 2024

Union City lost 3,737 residents from July 2020 to July 2024, a change of -5.3%. In the latest year it moved by -16. Among 429 California places of 5,000 or more, that growth ranks 421st; the median place changed by -1.1%. The median place of 5,000+ in California has 37,056 people, so Union City is 1.8 times that size.

Union City covers 19.40 square miles of land, for 3,412 people per square mile of land. The median California place of 5,000+ has 3,725, so Union City is close to the typical town.

What county Union City is in

All of Union City's residents live in Alameda County, which had 1,649,060 residents in 2024. Union City holds 4.0% of the county's population. The shaded shape is on the map above; dots mark the eight nearest places.

ZIP codes in Union City

2 ZIP Code Tabulation Areas (ZCTAs) overlap Union City by at least 10% of the ZCTA's or the city's land: 94552, 94587. ZCTAs are Census approximations of USPS ZIP code delivery areas. The list comes from the 2020 ZCTA to place relationship file, so a city that annexed land after 2020 may reach into ZIP codes not listed here.

Where Union City is

The Census internal point of Union City is at 37.602800, -122.018800. Sacramento, the capital, is 73.1 miles NNE in a straight line. The nearest larger place is Hayward, CA (158,440 people), 5.0 miles away.

Daylight in Union City

At 37.60° N, Union City gets about 14 h 46 min of daylight around the June solstice and 9 h 34 min around the December solstice, a swing of 5 h 12 min. Figures are sunrise to sunset from the SunCalc model for June 21 and December 21, 2026.

Places near Union City

The eight nearest incorporated places of 1,000+ in California, measured between internal points. The closest is Hayward, 4.9 miles away, with 158,440 people.