During this year's heat wave I learned something new about the heat index that I didn't know before. I had always thought that the high humidity levels were the major cause of the high heat indexes but, on this past Tuesday when the heat index was 108 degrees. I noticed that the humidity levels weren't that high and the dew point levels were. The humidity level was 46% and the dew point level was 70. So I learned that the high dew point levels were the cause of the high heat indexes not the humidity levels. Although they can still help to rise the heat index though. So, that means that having a chance for rain like we did on Tuesday is not necessarily a good thing because if we don't get the rain and we get really high dew point levels then it could make it seem a lot hotter outside. Which isn't good for a city like Houston that already gets hot temperatures during the summer months. I'm glad that we've been getting some rain though.