As the heat rises this weekend, so will the humidity. Now, the humidity won't be extreme, but will nudge the heat indices to the mid-upper 90s, a few degrees higher than the actual temperature. Take a look at the heat index tracker below, its going to be rather steamy outside, especially from around 1 - 7pm. Check out how we calculate the heat index below.
So, obviously, the heat index is a function of heat and humidity. You can calculate the heat index by inputting the actually humidity or dew point. We normally use dew points. So, how do you find the dew point? Look at the screen shot below. This is the Local Aviation MOS program, or short range numerical forecast. Don't worry too much about all the different numbers, but look at the 3rd line down (DPT), those are the dew points. The time of day is the 1st line (UTC), which is Zulu time, to make it simple, 12z is 8am, 16z is noon, 18z is 2pm, 20z is 4pm, 00z is 8pm. What we'll do is find the time of day, look for the matching dew point, then put that number with the temperature forecast (2nd line = TMP = temperature) and calculate the heat index. Use the heat index calculator link here to make the calculation.