This calculator requires the use of Javascript enabled and capable browsers. This script calculates the Heat Index ( or "feels like" temperature) from the relative humidity or from the dew point, along with the ambient air temperature in degrees Fahrenheit (F). In either calculator, enter the temperature in degrees (F) and the other factors (numerical entry only); then click on Calculate. The calculator will return the Heat Index and other relative information. You may independently clear the values of either calculator to start over. The heat Index does not really occur below 85 degrees F. You should also know that possible increases of up to 15 degrees F are possible in full, open sunlight for more than an hour. We have also provided tables below the calculators for those that don't feel like entering data and clicking the mouse. If you are confused by Fahrenheit and Celsius, there is a converter as a part of the calculator. Enter data in either field and click anywhere in the calculator for the result to appear. (Whew... with that behind us, the heat is OFF!) For those of you that are capable of mental math with a pencil and are up to a challenge, try this by hand. If you would like to make a manual calculation of the Heat Index, here is the formula:
The formula variables are: HI = Heat Index, T = Temperature (°F), RH = Relative Humidity (%)
