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 don't create or modify the underlying data. We join it spatially 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.

NERIS Public also includes an incident feed ("NERIS Public Incident Basics"): incident reports with broad type categories and timestamps, published by departments as they adopt NERIS. Department pages use it for the Reported Incident Activity section: headline counts over the trailing 12 complete months. Known limitations: coverage varies by department while the NERIS transition is under way, so counts reflect what a department has published rather than necessarily every call it ran; mutual aid given is included; and the feed carries no response times or outcomes.

Both datasets are open on ArcGIS Hub: department boundaries and incident reports. Each department page links directly to that department's own rows in both, so you can verify anything on the page against the source records.

Departments with boundaries
~24,500
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 2025), 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 →

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, reach out and we'll take a look.

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