Arborlook
Risk & Response by Arborlook Insights

Data Sources

Every data source behind the free risk profiles — what it is, what it covers, and how current it is.

All free tier data is from public sources. We do not create or modify the underlying data — we integrate, spatially join, and present it. The original datasets are freely available from the agencies listed below. Where data has known limitations (age, coverage gaps, methodology caveats), we've noted them.

Department & Station Data
NERIS Public
Fire Safety Research Institute (FSRI) / UL Research Institutes
Free Ongoing updates

The National Emergency Response Information System (NERIS) is the modern national incident reporting system for the U.S. fire service, replacing NFIRS. The public dataset provides department boundaries (jurisdictional polygons), station locations, department names, department type (career/combination/volunteer), and basic organizational metadata for enrolled departments.

Department pages on Risk & Response are generated for all NERIS Public departments with a valid boundary polygon. Department names, boundaries, and station counts displayed on each page come directly from NERIS without modification.

Departments with boundaries
~22,000
Station records
~62,000
Coverage
50 states + DC
neris.fsri.org →
Demographics & Socioeconomics
American Community Survey (ACS) 5-Year Estimates
U.S. Census Bureau
Free Annual release

The American Community Survey is an ongoing Census Bureau survey that produces estimates of demographic, social, economic, and housing characteristics for communities across the United States. The 5-year estimates pool five years of survey responses to produce reliable estimates at small geographies — including the census tract level used throughout Risk & Response.

We use the 2020–2024 5-year estimates (released December 2024), which are the most recent available. ACS estimates have associated margins of error, which are larger for small populations and rare characteristics. Metrics are displayed as-is from ACS; we do not smooth or adjust estimates.

Vintage
2020–2024
Census tracts
85,382
Variables used
194 raw + 38 derived
Coverage
50 states + DC + PR
Key Variable Groups
Age distribution Disability status Poverty rate Health insurance coverage Median household income Median home value Per capita income Housing age Heating fuel type Housing structure type Vacancy rate Renter-occupied % Vehicle access Internet access Limited English proficiency
census.gov/acs →
Hazard Risk
National Risk Index (NRI)
FEMA / Federal Emergency Management Agency
Free Periodic releases

The National Risk Index is FEMA's dataset of natural hazard risk at the census tract level. For each of 18 natural hazard types, NRI provides a risk score (0–100, representing relative national risk), a risk rating (Very Low through Very High), and an Expected Annual Loss estimate in dollars. Scores integrate hazard frequency/magnitude, community exposure, and social vulnerability.

We use NRI version 1.2 (December 2025). NRI scores are displayed on a fixed national scale — they are not adjusted or renormalized. A score of 80 means the tract is in the top 20% of risk nationally for that hazard, regardless of which department page you're viewing.

Version
v1.2 (Dec 2025)
Census tracts scored
85,154
Hazard types
18
Score range
0.02 – 100
18 Hazard Types
Avalanche Coastal Flooding Cold Wave Drought Earthquake Hail Heat Wave Hurricane Ice Storm Landslide Lightning Riverine Flooding Strong Wind Tornado Tsunami Volcanic Activity Wildfire Winter Weather
hazards.fema.gov/nri →
Disaster History
Disaster Declarations Summaries
FEMA / OpenFEMA
Free Continuously updated

OpenFEMA provides machine-readable access to all Presidential and Secretarial Major Disaster Declarations and Emergency Declarations going back to 1953. Each declaration record includes the declaration type, incident type (flood, severe storm, hurricane, etc.), date, and affected counties.

We match declarations to departments by county FIPS code. Statewide declarations (county code "000") are excluded. The dataset is continuously updated as new declarations are issued; our free tier pages reflect declarations through early 2026 and are refreshed annually.

Declarations in our counties
65,108
Date range
1959 – 2026
Counties covered
3,113
Top Incident Types
Severe Storm Hurricane Flood Biological Tornado Snowstorm Fire Earthquake
fema.gov/openfema →
Critical Infrastructure
Homeland Infrastructure Foundation-Level Data (HIFLD)
DHS / CISA
Last public release: 2025

HIFLD is a DHS/CISA program that publishes point-level data on critical infrastructure facilities across the United States. We use five facility layers: hospitals, nursing homes, public schools, private schools, and child care centers. Each facility record includes location, name, address, and facility-specific attributes.

Note: HIFLD data is no longer publicly available as of 2025. We are using the last public release. Facility counts on department pages reflect that snapshot and will not be updated until a new public release is made available.

Facilities are spatially joined to department boundaries — a facility is counted for a department if its point location falls within the department's boundary polygon. Approximately 85% of facilities match to a department; the remainder are in unincorporated or rural areas with no NERIS boundary coverage.

Total facilities
315,948
Hospitals
8,220
Nursing homes
53,059
Public schools
100,983
Private schools
22,134
Child care centers
131,552

Questions about the data?

If a metric on your department's page looks incorrect, or you have questions about how a specific data source is used, email us and we'll take a look.

[email protected]