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HomeRiskIQ guide

How the HomeRiskIQ score is calculated

A transparent breakdown of hazard inputs, normalization, and how composite risk is assembled.

9 min readUpdated 2025-12-22ScoringFloodWindSurgeLightningTornadoHail

What goes into the score

HomeRiskIQ blends multiple hazards into a 0-100 score. Each hazard is scored separately, then combined into a composite.

The score prioritizes hazard availability, so missing coastal surge does not penalize inland locations.

Grid resolution and coverage

Most baseline hazard layers are stored as 0.1-degree tiles (about 6 miles). Each tile carries a score and an availability flag.

Availability prevents missing data from pulling scores down in regions where a hazard does not apply.

Normalization and percentiles

Raw datasets are normalized using percentile thresholds to prevent extreme outliers from flattening the map.

Percentile cuts keep regional differences visible while still highlighting the highest risk zones.

Composite logic

Flood is always included when available. Other hazards contribute when the score is above zero.

For coastal areas, surge provides an extra weighting in hurricane composite views.

Baseline vs live overlays

Baseline scores come from long-term climatology or historical datasets.

Live overlays (alerts, outlooks, current storms) add time-sensitive context without rewriting the baseline tiles.

How to interpret the number

The score is relative exposure, not a guarantee of loss. Use it to compare neighborhoods or plan upgrades.

Combine it with live alerts and outlooks to decide what matters today.

Key takeaways

  • - Scores blend hazard models into a single 0-100 index.
  • - Percentiles keep the map meaningful across regions.
  • - Missing hazards do not penalize inland cities.
  • - Use scores for planning and comparison, not prediction.