INDIANAPOLIS – Another hot week of weather is underway across Central Indiana with high temps reaching the upper 80s on this Monday. If you have been outside at all, you may notice that the heat does not feel so overbearing, at least in comparison to last week. Lucky for us, today is no fluke! More comfortable heat, relatively speaking, is on the way this week…

Diving into dew point

Dew point is a measure of moisture in the air. To be exact, it represents the temperature that a given volume air must cool for water vapor to condense into a liquid. However, you probably know it more simply as a measure of humidity.

When the dew point is lower than 60 degrees, it means there is a fairly low amount of moisture distributed through the air and the temperature must drop quite a bit for it to condense into something like fog. Generally, this level of humidity is negligible and the air is comfortable. When the dew point is in the 60s or higher, water vapor is found at higher concentration and will condense much easier. It also means the air will feel more sticky.

The difference of dew point

When it is more humid and dew points are higher, the sweat on your skin evaporates at a much slower rate. As a result, you will not cool off as efficiently and it will leave you feeling hotter. This is captured by the heat index or feels-like temperature, which will be higher than actual air temps on humid days. When it’s more dry outside, the opposite comes into play with those feels-like temps often matching the actual air temp.

Humidity also plays a role in determining how hot it gets too. Water vapor is a greenhouse gas and requires more energy to heat up and cool down. When it’s humid, it will be harder to achieve hotter temperatures during the day, but it will also be tougher to cool off quickly at night. Dry air on the other hand will feature larger diurnal (day to night) temperature swings.

This week’s weather it’s the relationship to dew point

Last week was very hot and humid. High temperatures were in the range of 91-93 degrees for four straight days. The heat index even broke 100 degrees on a number of those days with a few record high low temps being broken. It certainly did not feel comfortable and required a lot more from the AC to cool things off.

This week it will all be much different. Dew points will remain at or below 60 nearly everyday with the exception of Wednesday. High temperatures may be higher, in the mid 90s, as a result. However, it will not feel as hot thanks to the lack of humidity. You will still need to be conscious of the hot weather, but as far the outdoors go, you’ll probably find this week to be much more pleasant!