Union City, California
37 topographic sheets cover this place, the earliest surveyed in 1899 and the latest in 1997. It stands in the Fremont census division. It lies in ZIP code area 94587. It stands on Dry Creek. The Survey maps it on the Newark quadrangle. 70,143 people lived here at the 2020 count. It stands 69 feet above sea level.
Then and now
1899 to 1997The same ground, surveyed 98 years apart. Drag the handle to wipe between them. Both sheets are United States Geological Survey originals; neither has been altered.


Population over time
2 figuresUnion City grew from 69,516 to 70,143 between 2010 and 2020. These are the recorded population figures Wikidata holds for this place, reached through the Geographic Names Information System number this page is keyed on rather than by name, so they belong to this place and not to another of the same name. Most are census counts, but not all are: an early figure may be a founding or settlement estimate, and an estimate published within five years of a census is left out. The change column is computed, and is left blank where more than 20 years separate a figure from the one before it, because a gap that long is not a change between two counts.
| Year | People | Change |
|---|---|---|
| 2010 | 69,516 | |
| 2020 | 70,143 | +627 (+1%) |
Topographic sheets covering this place
21 surveys from 37 printed sheetsMatched by testing this settlement's coordinate against the published boundary of every sheet in the United States Geological Survey's historical collection. Each opens the scanned sheet at the Survey.
- 1899 USGS Haywards quadrangle1:62500, 5 printings
- 1915 USGS Hayward quadrangle1:62500, 2 printings
- 1915 USGS Haywards quadrangle1:62500, 2 printings
- 1942 USGS Hayward quadrangle1:62500
- 1947 USGS Newark quadrangle1:24000
- 1947 USGS San Francisco quadrangle1:250000
- 1948 USGS Newark quadrangle1:24000
- 1948 USGS San Francisco quadrangle1:250000
- 1955 USGS San Francisco quadrangle1:250000
- 1956 USGS San Francisco quadrangle1:250000, 4 printings
- 1957 USGS San Francisco quadrangle1:250000
- 1959 USGS Hayward quadrangle1:62500, 2 printings
- 1959 USGS Newark quadrangle1:24000, 6 printings
- 1960 USGS San Francisco quadrangle1:250000
- 1961 USGS San Francisco quadrangle1:250000
- 1964 USGS San Francisco quadrangle1:250000
- 1971 USGS San Francisco quadrangle1:250000
- 1978 USGS San Francisco quadrangle1:100000, 2 printings
- 1985 USGS San Francisco quadrangle1:250000
- 1993 USGS Newark quadrangle1:24000
- 1997 USGS Newark quadrangle1:24000
Fires near this place
315 since 1992Regional context, not property-specific evidence. The federal wildfire occurrence database lists 315 fires within 5 miles of Union City between 1992 and 2020, burning about 1,516 acres in total. None started naturally. 34 were recorded as arson. Distance is straight-line from the map coordinates, so a fire counted here may appear on a neighbouring settlement's page as well.
| Reported cause | Fires |
|---|---|
| Missing data/not specified/undetermined | 226 |
| Arson/incendiarism | 34 |
| Equipment and vehicle use | 22 |
| Smoking | 12 |
| Misuse of fire by a minor | 10 |
| Debris and open burning | 8 |
| Recreation and ceremony | 3 |
The most recent of them, most recent first, with the day each was reported and the service that recorded it.
| Date | Cause | Size | Reported by | Name on the report |
|---|---|---|---|---|
| 9 September 2010 | Missing data/not specified/undetermined | 1.0 acres | California Department of Forestry & Fire Protection | not named |
| 9 September 2005 | Smoking | under an acre | California Department of Forestry & Fire Protection | not named |
| 9 September 2004 | Missing data/not specified/undetermined | under an acre | Santa Clara Unit | 84 |
| 9 September 2003 | Missing data/not specified/undetermined | under an acre | Santa Clara Unit | WINERY |
| 8 September 2010 | Missing data/not specified/undetermined | under an acre | California Department of Forestry & Fire Protection | not named |
| 7 September 2008 | Missing data/not specified/undetermined | 1.0 acres | Santa Clara Unit | PIONEER |
| 29 September 2016 | Debris and open burning | under an acre | California Department of Forestry & Fire Protection | not named |
| 27 September 2020 | Missing data/not specified/undetermined | 2.5 acres | Santa Clara Unit | not named |
Settlements close enough to share some of these fires:
Mines and quarries near this place
10 of 42 shownRegional context, not property-specific evidence. The federal mineral resources record lists 42 workings within 5 miles of Union City: 19 producers, 18 past producers, 5 occurrences. 19 still produce. What was taken out: Sand and Gravel, Construction, Clay, Stone, Stone, Crushed/Broken. Distance is straight-line from the map coordinates, so a quarry counted here may appear on a neighbouring settlement's page as well.
| Where | Site | Commodity | Status | Recorded |
|---|---|---|---|---|
| Interpace | Fire Clay (Refractory), Kaolin, Silica | Producer | ||
| Morton Salt Co. | Halite | Producer | ||
| Oliver Salt | Salt | Producer | ||
| Taylor and Pitcher | Manganese, Salt, Silica | Past Producer | ||
| Bellini Quarry | Stone, Crushed/Broken | Producer | ||
| Dumbarton Mill | Stone, Crushed/Broken | Producer | ||
| East Bay Excavation Co | Stone, Crushed/Broken | Producer | ||
| Niles Quarry | Stone, Crushed/Broken | Producer | ||
| Clay Pit | Clay | Past Producer | Sedimentary | |
| Durham Pit | Stone | Producer |
Nearest settlements
The eight closest, with where each one stands in the county. Distances are straight-line, computed from the Geographic Names Information System coordinates.
| Map | Place | Distance | Sheets |
|---|---|---|---|
| Pabrico | 1.1 miles | 37 | |
| Carpenter | 1.8 miles | 37 | |
| Eberly | 2.1 miles | 26 | |
| Niles District | 2.5 miles | 26 | |
| Hall Station | 2.5 miles | 37 | |
| Halvern | 2.7 miles | 36 | |
| Shinn | 2.8 miles | 26 | |
| Niles Junction | 2.9 miles | 26 |
Elsewhere
Matched on this settlement's Geographic Names Information System number rather than its name, so it cannot be a different place of the same name in another state.
| Wikipedia article on Union City | An encyclopaedic summary. Its text is share-alike, so it is linked here rather than copied. |
| Wikidata item Q846402 | The structured record the population and elevation above come from. Public domain (CC0). |
Provenance
This settlement is recorded in the Geographic Names Information System as feature 236787. The sheet list is computed by point-in-boundary test against the United States Geological Survey's historical topographic inventory. Both are works of the United States government and carry no copyright under 17 U.S.C. 105.
Wildfire. Short, Karen C. 2022. Spatial wildfire occurrence data for the United States, 1992-2020 [FPA_FOD_20221014]. 6th Edition. Fort Collins, CO: Forest Service Research Data Archive. https://doi.org/10.2737/RDS-2013-0009.6 Collected with United States Government funding and usable without additional permissions or fees.
Mines and quarries. USGS Mineral Resources Data System (MRDS) https://mrdata.usgs.gov/mrds/ A work of the United States government, no copyright under 17 U.S.C. 105.




















