Methodology
How a report is built, how each finding is rated, and where every number comes from.
The address
You choose a US street address from the search box. When it has a house number, the point is re-checked against the US Census Bureau’s geocoder before anything else runs, and the report says which match it used. Everything below is measured from that point.
What is measured, and how far out
| Topic | Study area |
|---|---|
| Nearby places, schools listed, and counts | 3 miles around the address |
| Map overlays: flood zones, wildfire hazard, noise and nuisances, schools | 5 miles |
| Everyday places on foot | 1,200 m, about a 15-minute walk |
| Tornado tracks | 9 miles |
| Tropical storm and hurricane tracks | 50 miles |
| Earthquakes | 50 km (31 miles) |
| Superfund sites | 10 miles |
| Rail, highways, power lines | 3 km (1.9 miles) |
| Industrial sites, landfills, wastewater plants | 5 miles |
| Federal disaster declarations | The county, last 20 years |
| Reported crime | The city's police agency; otherwise the nearest agency within 25 miles, flagged as matched by distance |
Distances are straight lines, not driving distances. Flood zone, elevation, streams, drinking water, radon, rents, housing allowance, and the census figures are looked up for the exact point or the tract, ZIP code, county, or water system that contains it.
How findings are rated
Every finding carries a severity and a confidence.
| Severity | Meaning |
|---|---|
| High | A documented condition that often changes a decision, such as a Very High FEMA hazard rating. |
| Moderate | Worth weighing before you commit, such as a Relatively High hazard rating or fine particle pollution above EPA's annual standard. |
| Low | Noted so you can plan for it, such as a Relatively Moderate hazard rating or nothing within walking distance. |
| Info | Context with no particular concern attached. |
Confidence says how directly the data describes this address: high when it was recorded for the point or parcel, moderate when it is modeled or covers a wider area such as a census tract, and low when the match itself is uncertain.
Where it helps, a finding is compared with the rest of the state and the country: the share of census tracts, counties, or police agencies with a lower value. Air quality also names the EPA Air Quality Index category that the annual averages for fine particles and ozone fall in, as a description of a typical day.
What we leave out on purpose
- No overall score or letter grade. Each finding stands on its own, with its source.
- No race, ethnicity, or other demographic data, and no anonymous reviews or sentiment.
- School ratings are not shown, only which schools are nearest and what grades they serve.
Data sources and how current they are
Every dataset below is public. The report shows the source and its date on each finding; this table shows the whole collection and when we last refreshed it.
| Dataset | Data as of | Last refreshed |
|---|---|---|
| Agency-reported violent and property crime (12 months)FBI Crime Data Explorer · 400 rows · Public domain (FBI UCR). Agency coverage and reporting vary. | December 2025 | October 18, 2026 |
| Annual PM2.5 and ozone at air monitoring sitesUS EPA AirData (Air Quality System) · 2,051 rows · Public domain (US government). | December 2025 | October 23, 2026 |
| Annual PM2.5 and ozone by census tract (EPA Downscaler)CDC National Environmental Public Health Tracking Network · 83,776 rows · Public domain (US government). Modeled by the EPA Downscaler; source: Centers for Disease Control and Prevention, National Environmental Public Health Tracking Network. Interpretations are not those of CDC. | December 2022 | October 23, 2026 |
| Basemap vector tiles (PMTiles extract)Protomaps daily build · 1 rows · Map data © OpenStreetMap contributors (ODbL); credit OpenStreetMap on every map. Protomaps basemap code is BSD-3-Clause. | October 2026 | October 23, 2026 |
| Basic Allowance for Housing ratesDefense Travel Management Office · Public domain (US government). | — | Not loaded yet |
| City boundariesUS Census Bureau TIGERweb · 883 rows · Public domain (US government). | — | October 31, 2026 |
| Community water system service areasUS EPA Community Water System Service Area Boundaries · 44,613 rows · Public domain (US government). About 40% of boundaries are modeled by EPA. | — | October 23, 2026 |
| Disaster declarationsOpenFEMA · 70,572 rows · Public domain (FEMA). Not endorsed by FEMA. | October 2026 | October 23, 2026 |
| Earthquakes M3.5+ since 1970USGS ComCat · 47,960 rows · Public domain (USGS). | October 2026 | October 23, 2026 |
| EPA radon zones by countyUS EPA Map of Radon Zones · 3,139 rows · Public domain (US government). The map dates from 1993; EPA says it is not for deciding whether to test. | — | October 23, 2026 |
| Historical tornado tracks, 1950 to presentNOAA Storm Prediction Center · 73,456 rows · Public domain (NOAA). | December 2025 | October 23, 2026 |
| Hospitals with an emergency department and their phone numbersCMS Hospital General Information · 4,186 rows · Public domain (US government). | July 2026 | November 4, 2026 |
| HUD Fair Market Rents (county and ZIP)HUD USER · Public domain (US government). | — | Not loaded yet |
| Median gross rent by census tract (ACS 5-year)US Census Bureau American Community Survey · 85,382 rows · Public domain (US government). This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau. | December 2024 | October 23, 2026 |
| Military installationsDoD MIRTA · 820 rows · Public domain (US government). Planning use only; not survey grade. | — | October 23, 2026 |
| Monthly climate normals by station (temperature, precipitation, snowfall)NOAA NCEI US Climate Normals 1991-2020 · 6,719 rows · Public domain (US government). | December 2020 | November 3, 2026 |
| National Risk Index (census tracts)FEMA National Risk Index · 85,154 rows · Public domain (FEMA). Not endorsed by FEMA; cite NRI version and access date. | December 2025 | October 23, 2026 |
| NFIP flood insurance claims and policies (aggregated)OpenFEMA FIMA NFIP redacted claims and policies v3 · 321,107 rows · Public domain (US government). Cite OpenFEMA per its terms; FEMA does not endorse this product. | September 2026 | October 23, 2026 |
| Photon geocoder index (USA)GraphHopper Photon database dumps · 1 rows · Data © OpenStreetMap contributors (ODbL). Photon software is Apache-2.0. | October 2026 | October 18, 2026 |
| Plant hardiness zones (half-zones, 1991-2020 extreme minimum temperature)USDA Plant Hardiness Zone Map, 2023 (USDA-ARS and Oregon State University) · 203,812 rows · Owned by Oregon State University; free to reproduce and redistribute. Maps derived from the data must show the USDA-ARS and OSU logos. Altered data needs a disclaimer that it is not the official map, and no logos. | December 2020 | November 4, 2026 |
| Points of interest (hospitals, veterinarians, shopping, schools, parks, ...)OpenStreetMap via Geofabrik · 543,429 rows · ODbL 1.0. Attribution: (c) OpenStreetMap contributors. | October 2026 | October 23, 2026 |
| Population and land area by census tract and place (ACS 5-year, Gazetteer)US Census Bureau American Community Survey and Gazetteer Files · 117,712 rows · Public domain (US government). This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau. | December 2024 | October 23, 2026 |
| Public and private schools and school districtsNCES EDGE · 135,953 rows · Public domain (US government). | — | October 23, 2026 |
| Rail lines, National Highway System and transmission linesBTS NTAD rail network and NHS; HIFLD electric transmission lines · 812,387 rows · Public domain (US government). | — | October 23, 2026 |
| Superfund National Priorities List sitesUS EPA (SEMS via FRS) · 1,765 rows · Public domain (EPA). | — | October 23, 2026 |
| TRI facilities, wastewater plants and landfillsUS EPA FRS, TRI and LMOP · 76,268 rows · Public domain (US government). | — | October 23, 2026 |
| Tropical cyclone best tracks (North Atlantic, East Pacific)NOAA NCEI IBTrACS v04r01 · 166,159 rows · Public domain (NOAA). Cite IBTrACS v04r01. | October 2026 | October 23, 2026 |
| US airports with scheduled service codesOurAirports · 873 rows · Public domain; no accuracy guarantee. | October 2026 | October 23, 2026 |
| US House members and congressional district boundariesOffice of the Clerk, US House of Representatives; Census TIGERweb · 1,323 rows · Public domain (US government). | — | October 23, 2026 |
| Wildfire hazard potential (High and Very High areas, 270 m)USDA Forest Service Wildfire Hazard Potential, 2023 version · 1,134 rows · Public domain (US government). | December 2023 | November 3, 2026 |
Each report also queries, at the time you build it, the US Census geocoder, FEMA’s flood map service, the US Geological Survey’s elevation and hydrography services, EPA’s drinking water data, and Wikipedia.
Limits
Public data has gaps and lags. OpenStreetMap coverage varies by town, crime figures depend on what each agency reports to the FBI, modeled air values cover a whole tract, and flood maps change. Each report ends with a list of what to verify and who to ask. Reports are informational and are not professional, legal, insurance, or inspection advice.
Found an error? Tell us and we will trace it back to the source.