California location data
Isopleth answers questions about any coordinate or street address in California with 351 public-data fields from 95 sources: flood and wildfire risk, soils and slope, the power grid, water and roads, climate, and county economics. Each value carries its source, license and vintage. Use it from the REST API or through the MCP server in Claude, ChatGPT, Cursor and other assistants.
Parcel coverage in California
Parcel records: 3,719,435 parcels in 5 of California's 58 counties, loaded county by county from layers each county publishes for reuse: Los Angeles (2,433,287), Santa Clara (504,995), Sacramento (502,215), San Francisco (227,700), Napa (51,238). Refreshed quarterly.
Share of parcels with each column filled: site address 95%, total value 65%, land use 80%, zoning 6%, year built 73%. Not published here: owner name, sale date.
Sample values in California
What our API returned at the Census Bureau's interior point of California's 3 largest counties by land area, computed 2026-10-29. One point is not a whole county: values can change within a few hundred meters, so look up your own site. "No data" means the dataset has nothing at that point.
| field | San Bernardino County | Inyo County | Kern County |
|---|---|---|---|
| Hazards | |||
| FEMA flood zone | D | X | X |
| Inside a mapped floodplain | No | No | No |
| Wildfire, annual frequency | 0.00082 events a year | 0.0022 events a year | 0.018 events a year |
| Tornado, annual frequency | 0.13 events a year | 0.070 events a year | 0.014 events a year |
| Hail, annual frequency | 0.068 events a year | 0.022 events a year | 0.095 events a year |
| Current drought category | D0 | D1 | D0 |
| On a mapped wetland | Yes | No | No |
| Nearest mapped wetland | 0 m | 412 m | 58 m |
| Land | |||
| Elevation | 396 m (1,298 ft) | 1,532 m (5,026 ft) | 373 m (1,225 ft) |
| Slope | 0.0° | 24.9° | 14.9° |
| Soil drainage | Somewhat excessively drained | Well drained | Well drained |
| Soil hydrologic group | A | D | C |
| Farmland class | Prime | Prime | Prime |
| Land use | Non-Forest Wetland | Other | Other |
| Crop or cover (CDL) | Barren | Shrubland | Grass/Pasture |
| Tree canopy | 0% | 0% | 0% |
| On protected land (PAD-US) | Yes | Yes | No |
| Surface manager | Blm | Nps | Private or unknown |
| Climate & energy | |||
| Annual precipitation (normal) | 84 mm (3 in) | 105 mm (4 in) | 314 mm (12 in) |
| Days above 32 °C a year | 158 days | 92 days | 123 days |
| Solar resource (GHI) | 5.83 kWh/m²/day | 5.83 kWh/m²/day | 5.47 kWh/m²/day |
| Mean wind speed at 100 m | 4.7 m/s | 7.0 m/s | 3.4 m/s |
| Wind capacity factor | 22% | no data | 8% |
| Infrastructure | |||
| Nearest substation (69 kV+) | 20.4 km (12.7 mi) | 51.4 km (32.0 mi) | 8.9 km (5.5 mi) |
| Nearest gas pipeline | 6.9 km (4.3 mi) | 102.4 km (63.6 mi) | 2.6 km (1.6 mi) |
| Electric utility | COLORADO RIVER INDIAN IRR PROJ | SOUTHERN CALIFORNIA EDISON CO | PACIFIC GAS & ELECTRIC CO. |
| In a public water service area | No | No | No |
| Depth to water, nearest monitored well | 31.0 m (102 ft) | no data | 16.8 m (55 ft) |
| Nearest major road | 14.6 km (9.1 mi) | 16.9 km (10.5 mi) | 6.2 km (3.8 mi) |
| Nearest FCC antenna structure | no data | no data | 1.4 km (0.9 mi) |
| Community | |||
| Nearest fire station | no data | no data | 15.8 km (9.8 mi) |
| Nearest hospital | no data | no data | 17.8 km (11.0 mi) |
| Nearest school | no data | no data | 11.5 km (7.2 mi) |
| In an Opportunity Zone | No | Yes | No |
County pages
- San Bernardino County 20,068 sq mi of land
- Inyo County 10,197 sq mi of land
- Kern County 8,135 sq mi of land
Datasets that returned data at these points
| source | fields |
|---|---|
BLM_SMA Bureau of Land Management | surface_management_agency |
EIA_ATLAS U.S. Energy Information Administration | nearest_gas_pipeline_distance_m |
EIA_POWER U.S. Energy Information Administration | electric_utility_service_territory, nearest_substation_distance_m |
EPA_CWS_SERVICE_AREAS U.S. Environmental Protection Agency | within_water_service_area |
FCC_ASR Federal Communications Commission | nearest_antenna_structure_distance_m |
FEMA_NFHL Federal Emergency Management Agency | nfhl_flood_zone, within_floodplain_polygon |
FEMA_NRI Federal Emergency Management Agency | hail_annual_frequency, tornado_annual_frequency, wildfire_annual_frequency |
HUD_OPPORTUNITY_ZONES U.S. Department of Housing and Urban Development | in_opportunity_zone |
NOAA_NCEI_NCLIMGRID_DAILY National Oceanic and Atmospheric Administration | days_above_32c_annual_count |
NOAA_NCEI_NORMALS_GRIDDED National Oceanic and Atmospheric Administration | annual_precipitation_normal_mm |
NREL_REV_LANDBASED_WIND_SC_2024 NREL reV supply curves, Open Energy Data Initiative (OEDI) | wind_capacity_factor_pct |
NREL_SOLAR_RESOURCE_V1 NREL Solar Resource Data (NSRDB) | ghi_annual_kwh_m2_day |
NREL_WIND_TOOLKIT NREL WIND Toolkit (Draxl et al., 2015) | mean_wind_speed_100m_ms |
OVERTURE_PLACES © Overture Maps Foundation | nearest_fire_station_distance_m, nearest_hospital_distance_m, nearest_school_distance_m |
OVERTURE_TRANSPORTATION © Overture Maps Foundation, © OpenStreetMap contributors | nearest_major_road_distance_m |
PAD_US USGS Protected Areas Database of the United States (PAD-US) | intersects_protected_area |
USDA_CDL U.S. Department of Agriculture | cdl_class |
USDA_SSURGO U.S. Department of Agriculture | prime_farmland_classification, soil_drainage_class, soil_hydrologic_group |
USDM_CURRENT The U.S. Drought Monitor is jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, and the National Oceanic and Atmospheric Administration. Map courtesy of NDMC. | drought_category |
USFS_LCMS USDA Forest Service | land_use_class |
USFS_NLCD_TCC USDA Forest Service | tree_canopy_pct |
USFWS_NWI U.S. Fish and Wildlife Service | intersects_wetland, nearest_wetland_distance_m |
USGS_3DEP_COG U.S. Geological Survey | elevation, slope_degrees |
USGS_NWIS_OGC U.S. Geological Survey | nearest_groundwater_well_depth_to_water_m |
These are only the sources behind the fields sampled here. The full list is on Sources & licenses and every field is in the field catalog.
What people use it for in California
- Land buyers: screen a lot for flood zone, wetlands, slope, soils, road and water access before a site visit; search California parcels by county, acreage or land use. Buyers who want it written up can order a $29 report on Check the Land, which is built on Isopleth.
- Solar, wind and data-center siting: distance to transmission and substations, solar and wind resource, protected land.
- Insurance and lending: hazard frequencies and floodplain status for every address in a book.
- Real estate and research: county income, growth and house-price trends next to on-the-ground facts.
See use cases for prompts and the exact fields.
Try it
curl https://api.isopleth.dev/v1/fetch -H "Authorization: Bearer $ISOPLETH_KEY" \
-H "Content-Type: application/json" \
-d '{"lat": 34.856661, "lng": -116.181571, "preset": "site_selection"}'
Or ask your assistant: “Using Isopleth, what are the flood zone, slope and soil drainage at 34.8567, -116.1816?”
Next: Arkansas · Colorado · all states