Data credits
and licences.
Humid-heat measure: Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.
Weather data by Open-Meteo.com. Humid-heat data are used under CC BY 4.0. Hourly temperature and dew point were converted to heat-index day counts and decade means.
Public-domain US government data from FEMA, NOAA, NASA and the US Census Bureau.
What each agency provides
- FEMA: county natural-hazard ratings, expected annual loss, exposure and community resilience scores, and National Flood Insurance Program claim counts.
- NOAA: county climate records used for El Niño winters and the hot-day cross-check, and the Pacific index that defines strong El Niño winters.
- NASA: satellite-and-model climate data for the decade measures on each county page.
- US Census Bureau: county codes and the population centre used to sample each county.
- Copernicus (ECMWF): hourly reanalysis behind the humid-heat measure.
How Climate Atlas uses them
We combine these public records into county measures, check every published number against the downloaded source before release, and label each value with its period and unit. Values are county context, not property findings.
Methods and limits for every measure are on the methodology page.
Reusing our county and state charts
The county loss charts and state county maps are drawn by Climate Atlas from the FEMA National Risk Index and are licensed CC BY 4.0. Reuse them with the credit "Climate Atlas, data: FEMA National Risk Index" and a link to the county page. The figures are modeled county totals, not forecasts for any property.
Questions about data credits
Where does Climate Atlas data come from?
From US government agencies (FEMA, NOAA, NASA and the US Census Bureau) and, for humid heat, from European reanalysis credited above.
Can I reuse the numbers?
Cite Climate Atlas and the agencies named here. Bulk or programmatic reuse of our compiled files is by request.
Why are some credits worded exactly?
Two licences require specific attribution wording; it appears once on this page.
County map boundaries
Map: US Census Bureau cartographic boundaries via us-atlas 3.0.1 (ISC licence). FEMA and boundary geographies can differ; unmatched counties have no FEMA estimate.