← Back to Tools🌡️ Heat Tool
Heat Index Risk Calculator
Estimate the heat index for shade and light wind. Direct sun, exertion and protective equipment require a separate heat plan; this is not a UV forecast.
15°C50°C
10%100%
⚠️
Approximate heat index — shade / light wind
33°C / 91°F
Extreme Caution
Heat cramps and heat exhaustion possible.
Clothing Recommendations
- ✓ Lightweight, loose clothing suited to the activity
- ✓ Check whether required equipment traps heat
- ✓ Plan shade and a cooler place to rest
- ✓ Use the separate UV forecast to choose sun coverage
Reduce activity intensity. Plan drinking water and rest breaks; follow local guidance for the activity.
Uses the NWS preliminary check, Rothfusz regression and low-/high-humidity adjustments. No UV rating follows from this result. Values beyond 125°F are shown as an upper category, not a precise prediction.