Advanced Hydrologic Prediction Service (AHOPS)
Mississippi River

















Interesting Weather Facts
HEAT INDEX
The Heat Index (HI) (or apparent temperature) is a measure of relative discomfort due to combined heat and high humidity. It was developed by R.G. Steadman (1979) and is based on physiological studies of evaporative skin cooling for various combinations of ambient temperature and humidity. As temperatures climb above 90°F and humidity goes above 40 percent, conditions are ripe for heat-related illnesses.