Data Sources & Methodology
ZipRiskMap aggregates publicly available government data to create a unified risk profile for every US ZIP code. Here's exactly how we do it.
Data Sources
| Source | Data | Coverage | Update Frequency |
|---|---|---|---|
| FBI UCR | Crime rates (violent + property) | ~18,000 agencies | Annual |
| FEMA National Risk Index | 18 natural hazard scores | All US counties | Annual |
| USFS WHP | Wildfire hazard potential | All US counties | Every 2-3 years |
| NOAA NCEI | Severe weather events | All US counties | Monthly |
| FEMA OpenFEMA | Disaster declarations | All US counties | As declared |
| US Census | ZIP-to-county mapping | All US ZIPs | Annual |
Scoring Methodology
All risk scores are normalized to a 0-100 scale where 0 = lowest risk and 100 = highest risk.
Individual Risk Scores
| Risk Type | Method | Weight |
|---|---|---|
| Crime | Percentile rank of combined violent + property crime rates among all reporting cities | 30% |
| Flood | FEMA NRI flood composite score (already 0-100) | 20% |
| Wildfire | USFS 5-class WHP mapped to 0/25/50/75/100 | 20% |
| Severe Weather | Percentile rank of NOAA severe event count (last 10 years) by county | 15% |
| Disaster | Percentile rank of FEMA declaration count (last 20 years) by county | 15% |
Overall Score Formula
Overall = (Crime x 0.30) + (Flood x 0.20) + (Wildfire x 0.20) + (Weather x 0.15) + (Disaster x 0.15)
Risk Levels
0-20
LOW
21-40
MODERATE
41-60
HIGH
61-80
SEVERE
81-100
EXTREME
Data Resolution
Most government data is published at the county or city level, not at the ZIP code level. We map each ZIP code to its primary county using the Census Bureau's ZIP-to-county crosswalk file, then apply the county-level risk scores to the ZIP page.
This is the same approach used by industry leaders like Redfin, First Street Foundation, and RiskFactor.com. We believe in full transparency about our data resolution.
Frequently Asked Questions
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How accurate are the risk scores?Our scores are based on the best available public data from federal agencies. They represent relative risk compared to national averages. For specific insurance or property decisions, consult a licensed professional.
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How often is data updated?Different data sources update at different frequencies. FBI crime data is annual, FEMA disaster declarations are near real-time, and NOAA weather data is updated monthly. We refresh our aggregated scores quarterly.
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Why is crime weighted at 30%?Crime is the most commonly searched risk factor and has the most direct impact on daily life. The weighting reflects search demand and user priorities based on our research.
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Is ZipRiskMap affiliated with any government agency?No. ZipRiskMap is an independent service. We use publicly available government data but are not affiliated with, endorsed by, or connected to FEMA, FBI, NOAA, USFS, or any other government agency.