Free tool

Wet Bulb & WBGT Calculator

Enter the temperature and humidity to compute the wet-bulb temperature, wet-bulb globe temperature (WBGT), heat index, dew point and real feel — each graded by its danger level.

WBGT (shade)
heat stress out of direct sun
27.7°CModerate
Wet Bulb
evaporative cooling limit
25.8°CUncomfortable
Heat Index
feels-like in shade
37.1°CExtreme Caution
Real Feel
apparent temperature
36.7°CVery Hot
Dew Point
moisture / mugginess
23.3°COppressive
This shows shade WBGT. The real outdoor figure also depends on direct sun, which needs your location and time — get the live, in-sun WBGT for your spot .

Wet bulb vs. WBGT — what’s the difference?

The wet-bulb temperature is the lowest temperature air can reach by evaporating water into it — a direct measure of how much cooling your sweat can still provide. Near 35 °C (95 °F) wet-bulb, a healthy person can no longer shed heat even at rest in the shade.

Wet-bulb globe temperature (WBGT)is the broader heat-stress standard: it blends the wet bulb with air temperature and, outdoors, the black-globe temperature that captures direct sun and wind. It’s what the military, athletic associations and occupational-safety bodies use to set activity limits.

How this calculator works

Wet bulb uses the Stull (2011) approximation; heat index uses the NWS Rothfusz regression; dew point uses Magnus-Tetens; real feel uses the Australian Bureau of Meteorology apparent-temperature formula. The WBGT shown here is the shadeform (0.7 × wet bulb + 0.3 × air temp), since the full outdoor figure needs solar radiation for your exact location and time. The colors match our published methodology.

Want the real, in-sun WBGT for where you actually are — plus a 7-day forecast and a personal “safe for me” read? Open WetBulbTracker, or read WBGT vs. heat index.

Informational only — not a substitute for official heat warnings or medical advice. © 2026 WetBulbTracker.