How does humidity affect the heat index?

Answer 1

This is a short but accurate answer. Humidity can get more dense which forms little water droplets. These water droplets come together and from clouds. Under the right weather conditions the clouds can form big rain droplets wich causes precipitation.

Answer 2

Humidity affects the heat index by making it feel hotter than the actual air temperature. When humidity is high, the body's ability to cool itself through sweating is reduced, leading to a perceived increase in temperature. This can result in discomfort, increased risk of heat-related illnesses, and higher heat index values.

Answer 3

Higher humidity increase heat index because higher humidity resulted to lesser evaporation of water/sweat and poorer heat convey out of the human body.