How dangerous is the heat where you live — right now?

Methodology & sources

What the score means. HeatScore is a 0–100 index of how dangerous the coming 72 hours of heat are for human health at a given location. It is driven by the two factors most strongly linked to heat mortality in the scientific literature: extreme apparent ("feels-like") temperature during the day, and hot nights that prevent the body from recovering.

• Heat load: the peak forecast apparent temperature over the next 72 h, scaled so that ≤ 24 °C → 0 points and ≥ 43 °C → 88 points: 88 × (peak − 24) / 19.
• Tropical nights: each night with a minimum ≥ 20 °C adds 6 points; a minimum ≥ 24 °C adds 10 points (max 3 nights counted).
• The total is capped at 100. Levels: 0–39 Low · 40–59 Caution · 60–74 Danger · 75–89 Severe · 90–100 Extreme.

Data sources. Forecasts: Open-Meteo, which aggregates official numerical weather models (ECMWF, DWD ICON, Météo-France and others). City coordinates and search: Open-Meteo Geocoding / OpenStreetMap. Population figures are approximate urban populations used for map sizing and exposure totals only.

Roadmap (v2): neighbourhood-level urban-heat-island adjustment from Copernicus/Landsat satellite land-surface temperature, and vulnerability weighting from Eurostat age structure — the full model described on this site's launch plan.