We often assume that the further south we are, the hotter we get. And while that’s mainly true, it’s not always the case. Humidity – or the water content in the air – plays a big role in how we heat and cool.
The bottom line up front here is that the more moisture you have in the air – or the higher the humidity – the slower the temperature will rise and fall.
So let’s take a look at our forecast for today in Bismarck, for instance (6/23/21). With highs in the 90s and dew points in the 50s… this is very dry air. This means our relative humidity is around 20-30%. Air this dry will heat and cool quickly.
The more moisture, the slower the temperature will rise. So now let’s take a look at Miami, FL. With temps in the 80s and dew points in the 70s, that’s instant sweat! Relative humidity will be around 60%-70%. With this much moisture, Miami will heat and cool very slowly with overnight lows around 80° and highs in the mid-80s to upper 80s. But even though it’s technically cooler in Miami, it’s much harder to cool off because of the humidity level.
That’s because when it’s humid, it feels hotter. Our bodies are naturally around 98.6 degrees. When it’s hot outside and our body’s temperature naturally rises…sweat is then released from the skin. This is our body’s way of starting the cooling process… That sweat evaporates into water vapor… which is invisible moisture. This draws the heat out of our body through what’s called evaporative cooling.
But, on muggy days – or during humid conditions – sweat can’t evaporate easily from your skin… so that cooling isn’t happening. This keeps you warmer and leaves you feeling sticky.
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