What is the Heat Index?

The heat index is a measure of what the temperature feels like to a person experiencing the temperature in the shade with a light wind. The heat index takes into account the temperature and humidity levels in order to approximate what the temperature will feel like. A higher humidity will typically make the temperature feel higher than an equivalent temperature with a lower humidity level. For instance, a temperature of 80°F combined with a relative humidity level of 85% will feel like a temperature of 85°F.