States / Washington
Washington location data
Isopleth answers questions about any coordinate or street address in Washington 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 Washington
Parcel records: 3,321,713 parcels in 39 counties. Published by WaTech (Washington Parcels Project); counties (Public, attribution); Current annual compilation, refreshed annual.
Share of parcels with each column filled: site address 85%, total value 95%, land use 98%. Not published here: owner name, sale date, zoning, year built.
Sample values in Washington
What our API returned at the Census Bureau's interior point of Washington'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 | Okanogan County | Yakima County | Chelan County |
|---|---|---|---|
| Hazards | |||
| Inside a mapped floodplain | No | No | No |
| Wildfire, annual frequency | 0.023 events a year | 0.017 events a year | 0.023 events a year |
| Tornado, annual frequency | 0.0045 events a year | 0.044 events a year | 0.012 events a year |
| Hail, annual frequency | 0.085 events a year | 0.093 events a year | 0.066 events a year |
| Current drought category | D3 | D0 | D1 |
| On a mapped wetland | No | No | No |
| Nearest mapped wetland | 108 m | 238 m | 70 m |
| Land | |||
| Elevation | 787 m (2,582 ft) | 374 m (1,228 ft) | 1,281 m (4,203 ft) |
| Slope | 0.4° | 2.9° | 25.0° |
| Soil drainage | Well drained | no data | Well drained |
| Soil hydrologic group | A | no data | B |
| Farmland class | Prime if conditions met | no data | Prime |
| Land use | Other | Other | Forest |
| Crop or cover (CDL) | Grass/Pasture | Grass/Pasture | Evergreen Forest |
| Tree canopy | 0% | 0% | 76% |
| On protected land (PAD-US) | Yes | No | Yes |
| Surface manager | State | Bia | Usfs |
| Climate & energy | |||
| Annual precipitation (normal) | 373 mm (15 in) | 245 mm (10 in) | 970 mm (38 in) |
| Days above 32 °C a year | 13 days | 34 days | 0 days |
| Solar resource (GHI) | 3.76 kWh/m²/day | 4.26 kWh/m²/day | 3.79 kWh/m²/day |
| Mean wind speed at 100 m | 3.8 m/s | 3.2 m/s | 4.6 m/s |
| Wind capacity factor | 12% | 10% | 21% |
| Infrastructure | |||
| Nearest substation (69 kV+) | 20.9 km (13.0 mi) | 8.3 km (5.1 mi) | 9.2 km (5.7 mi) |
| Nearest gas pipeline | 129.8 km (80.6 mi) | 25.5 km (15.9 mi) | 52.1 km (32.4 mi) |
| Electric utility | PUD NO 1 OF OKANOGAN COUNTY | PACIFICORP | PUD NO 1 OF CHELAN COUNTY |
| In a public water service area | No | No | No |
| Depth to water, nearest monitored well | 2.4 m (8 ft) | 83.8 m (275 ft) | 3.0 m (10 ft) |
| Nearest major road | 14.7 km (9.1 mi) | 5.9 km (3.7 mi) | 9.2 km (5.7 mi) |
| Community | |||
| Nearest fire station | 21.9 km (13.6 mi) | 15.1 km (9.4 mi) | 9.4 km (5.8 mi) |
| Nearest hospital | 22.0 km (13.7 mi) | 7.0 km (4.4 mi) | no data |
| Nearest school | 17.8 km (11.1 mi) | 8.6 km (5.3 mi) | 10.7 km (6.7 mi) |
| County median household income | no data | $70,656 | no data |
| County population growth, 1 year | no data | +0.1% | no data |
| County house prices, year over year | no data | +3.6% | no data |
| In an Opportunity Zone | No | No | No |
County pages
- Okanogan County 5,266 sq mi of land
- Yakima County 4,294 sq mi of land
- Chelan County 2,921 sq mi of land
Datasets that returned data at these points
| source | fields |
|---|---|
BLM_SMA Bureau of Land Management | surface_management_agency |
CENSUS_ACS U.S. Census Bureau | county_median_household_income |
CENSUS_PEP U.S. Census Bureau | county_population_growth_1yr_pct |
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 |
FEMA_NFHL Federal Emergency Management Agency | within_floodplain_polygon |
FEMA_NRI Federal Emergency Management Agency | hail_annual_frequency, tornado_annual_frequency, wildfire_annual_frequency |
FHFA_HPI Federal Housing Finance Agency | county_hpi_yoy_pct |
HUD_OPPORTUNITY_ZONES U.S. Department of Housing and Urban Development | in_opportunity_zone |
JRC_PVGIS_NSRDB See source_url | ghi_annual_kwh_m2_day |
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_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 Washington
- Land buyers: screen a lot for flood zone, wetlands, slope, soils, road and water access before a site visit; search Washington 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": 48.548453, "lng": -119.742235, "preset": "site_selection"}'
Or ask your assistant: “Using Isopleth, what are the flood zone, slope and soil drainage at 48.5485, -119.7422?”
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