A few thunderstorms could still pop up in the region Wednesday afternoon, as some monsoonal moisture will stick around for another day, but the trend will be for things to stabilize as we head through the rest of the week. Temperatures will stay in the mid-90s through the work week before rising to the upper 90s over the weekend under clear skies.

Heat Index Chart

We’ve been talking about the Heat Index. Let’s say the temperature here in Reno and in Houston is 90 degrees F. In Reno, a dewpoint of 30 degrees is fairly common, which gives us a relative humidity of 12%. The Heat Index for these conditions is 86 degrees… in other words; it “feels” like 86 degrees. But in Houston, you can easily have a dewpoint of 75 degrees (61% humidity), and that gives you a Heat Index (HI) of 100 degrees. An 80 degree dewpoint (72% RH) causes the HI to soar to 107. So the amount of moisture in the air can make more than a 20 degree difference in comfort level.

But just why does the humidity make such a big difference in how hot it feels? I’ll tell you tomorrow.