What is Wet Bulb Temperature?

Wet bulb temperature is the lowest temperature that can be reached by the evaporation of water only. It is a unique measurement that combines air temperature (dry bulb temperature) and relative humidity. Unlike the standard temperature you see on a thermometer, the wet bulb temperature accounts for the cooling effect of evaporation. This makes it a critical metric for understanding how "coolable" an object or person can be in specific weather conditions.

How to Use the Wet Bulb Calculator

Using this tool is straightforward. Simply follow these steps:

• Input Temperature: Enter the current ambient air temperature.
• Select Unit: Choose between Celsius or Fahrenheit.
• Enter Humidity: Provide the relative humidity percentage (0-100%).
• Analyze Results: The calculator will instantly provide the wet bulb temperature using the Stull formula, which is accurate for standard sea-level pressures.

Why Wet Bulb Temperature Matters

Wet bulb temperature is vital for human safety and industrial efficiency. In meteorology, it helps predict snowfall and thermodynamic stability. However, its most critical application is in heat safety. Humans cool down by sweating; if the wet bulb temperature reaches 35°C (95°F), the air is so saturated with moisture that sweat can no longer evaporate. This can lead to fatal hyperthermia even in healthy individuals, as the body loses its ability to regulate internal heat.

Frequently Asked Questions

Is wet bulb temperature the same as the heat index?

No. While both measure heat stress, the heat index is a "feels like" temperature for humans in the shade. Wet bulb temperature is a physical measurement of evaporative cooling potential.

What is a dangerous wet bulb temperature?

Generally, a wet bulb temperature above 30°C is considered extremely dangerous for outdoor physical activity, while 35°C is considered the theoretical limit of human survivability for extended periods.