What the proxy measures
HomeNHealthy combines May–September mean temperature and precipitation from NOAA’s 1991–2020 U.S. Climate Normals. Warmth contributes 55% and precipitation 45% to a 0–100 moisture-pressure value. The inverse is used as one index component.
Why use climate normals?
Thirty-year normals describe a place’s typical climate more reliably than a single wet month or drought week. They help compare recurring warm-season conditions while avoiding a false claim that current weather changed the physical condition of every home in a city.
The station-selection rule
The updater checks nearby stations, prefers the same state, requires all 12 monthly temperature and precipitation records, and rejects stations with an implausible annual precipitation total. This prevents missing precipitation from silently appearing as twelve zeroes.
What it cannot establish
Mold and moisture damage depend on leaks, drainage, construction, ventilation, cooling, indoor humidity and maintenance. The proxy cannot diagnose any of those conditions. A dry-climate city can have a wet basement; a humid-climate home can be well controlled.
How to use it
Treat the value as background context for questions about dehumidification, drainage, building-envelope inspection and ventilation—not as a risk prediction for a property.