Connecticut location data
Isopleth answers questions about any coordinate or street address in Connecticut 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 Connecticut
Parcel records: 1,320,655 parcels in 9 counties. Published by CT GIS Office / Office of Policy and Management; 169 municipalities (Public, attribution); 2026 parcel + CAMA collection, refreshed annual.
Share of parcels with each column filled: owner name 98%, site address 98%, total value 97%, land use 96%, sale date 58%, zoning 94%, year built 87%.
Sample values in Connecticut
What our API returned at the Census Bureau's interior point of Connecticut'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 | Capitol Planning Region | Northwest Hills Planning Region | Southeastern Connecticut Planning Region |
|---|---|---|---|
| Hazards | |||
| FEMA flood zone | X | no data | X |
| Inside a mapped floodplain | No | No | No |
| Wildfire, annual frequency | 0.000032 events a year | 0.00012 events a year | 0.000024 events a year |
| Tornado, annual frequency | 0.0015 events a year | 0.014 events a year | 0.0012 events a year |
| Hail, annual frequency | 2.4 events a year | 3.0 events a year | 1.3 events a year |
| On a mapped wetland | No | No | Yes |
| Nearest mapped wetland | 113 m | 219 m | 0 m |
| Land | |||
| Elevation | 24 m (79 ft) | 418 m (1,370 ft) | 39 m (129 ft) |
| Slope | 3.7° | 7.5° | 0.4° |
| Soil drainage | Well drained | Well drained | Very poorly drained |
| Soil hydrologic group | B | C | B/D |
| Farmland class | Prime | Prime | Prime |
| Land use | Developed | Agriculture | Forest |
| Crop or cover (CDL) | Developed/Low Intensity | Fallow/Idle Cropland | Developed/Open Space |
| Dominant crop, 5 years | no data | Fallow/Idle Cropland | no data |
| Tree canopy | 42% | 27% | 53% |
| On protected land (PAD-US) | No | Yes | Yes |
| Surface manager | Private or unknown | Private or unknown | Private or unknown |
| Climate & energy | |||
| Annual precipitation (normal) | 1,169 mm (46 in) | 1,295 mm (51 in) | 1,187 mm (47 in) |
| Days above 32 °C a year | 14 days | 2 days | 6 days |
| Solar resource (GHI) | 4.03 kWh/m²/day | 3.88 kWh/m²/day | 4.10 kWh/m²/day |
| Mean wind speed at 100 m | 5.5 m/s | 8.2 m/s | 6.6 m/s |
| Wind capacity factor | 37% | 41% | 35% |
| Infrastructure | |||
| Nearest transmission line | 159 m | 1.6 km (1.0 mi) | 1.3 km (0.8 mi) |
| Nearest substation (69 kV+) | 1.9 km (1.2 mi) | 10.7 km (6.6 mi) | 1.7 km (1.1 mi) |
| Nearest gas pipeline | 7.7 km (4.8 mi) | 15.0 km (9.3 mi) | 2.4 km (1.5 mi) |
| Electric utility | FARMINGTON RIVER POWER COMPANY | CONNECTICUT LIGHT & POWER CO | CITY OF NORWICH - (CT) |
| In a public water service area | Yes | No | Yes |
| Depth to water, nearest monitored well | 2.4 m (8 ft) | 11.9 m (39 ft) | 5.8 m (19 ft) |
| Nearest major road | 425 m | 1.7 km (1.0 mi) | 73 m |
| Nearest FCC antenna structure | no data | no data | 1.2 km (0.7 mi) |
| Community | |||
| Nearest fire station | 983 m | 3.2 km (2.0 mi) | 558 m |
| Nearest hospital | 1.9 km (1.2 mi) | 9.3 km (5.8 mi) | 2.4 km (1.5 mi) |
| Nearest school | 1.0 km (0.7 mi) | 2.2 km (1.4 mi) | 1.1 km (0.7 mi) |
| In an Opportunity Zone | No | No | No |
County pages
- Capitol Planning Region 1,027 sq mi of land
- Northwest Hills Planning Region 787 sq mi of land
- Southeastern Connecticut Planning Region 598 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, nearest_transmission_line_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 |
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_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, dominant_crop_5y |
USDA_SSURGO U.S. Department of Agriculture | prime_farmland_classification, soil_drainage_class, soil_hydrologic_group |
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 Connecticut
- Land buyers: screen a lot for flood zone, wetlands, slope, soils, road and water access before a site visit; search Connecticut 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": 41.81697, "lng": -72.575886, "preset": "site_selection"}'
Or ask your assistant: “Using Isopleth, what are the flood zone, slope and soil drainage at 41.8170, -72.5759?”
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