Humidity is part of life during North Carolina summers.
This summer, however, has been one of the most humid on record in our area.
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Dew point vs. relative humidity
When we're talking about the humidity or mugginess, we're referring to the dew point. This is a more accurate measure of how things feel compared to relative humidity.
Cooler air holds less moisture. Therefore, it feels less muggy in the winter time (even if relative humidity is close to 100%).
Warmer air holds more moisture, which is definitely the case during North Carolina summers.
Let's put it this way. If your air temperature is 90 degrees and your dew point is 70 degrees, the relative humidity is around 51-52%. It feels very muggy out there, but a 51-52% humidity doesn't really convey that.
Once the dew point gets to 70 degrees, that's when the air feels tropical and heavy. That's something that we've seen every day but one in the month of August.
Dating back to July 1, there have only been four days in which the dew point hasn't gone above 70 degrees.
That's why Monday and Tuesday's break in the humidity has felt especially good.
Why so sticky this summer?
Our proximity to water is often going to be a source of our humidity in the summer. That doesn't change. However, the ocean water temperatures have changed.
Currently, ocean temperatures along the Gulf Stream are at least 2 degrees Celsius warmer than average.
If you back up the view, you can see that this warmth extends up toward New England and Canada's maritime provinces. Outside of that, much of the Atlantic and the Gulf is 1-2 degrees Celsius warmer than average.
So, when your typical Bermuda High pattern sets up, you're getting breezes from these warmer bodies of water.
Why should we care?
Remember what I said about warmer air holding more moisture. That ocean breeze means the dew point rises, adding insult to injury to our heat.
This is why Fayetteville has seen more than two dozen Heat Advisories issued this summer, whereas the average per year is nine.
This uptick in humidity is also why our overnights have been so warm.
Our summer lows have averaged as the fourth-highest on record in Raleigh (70.6 degrees) and tenth-highest on record in Fayetteville (70.9 degrees).
This leads to more demand on our A/C units, which leads to monthly bills being more expensive. And if you're like me, you had to replace your A/C unit already this summer.