Tuscarawas County
Level: advisory
Frost Advisory
Location: Belmont, Carroll, Columbiana, Coshocton, Guernsey
Start: 10/19/2019 06:32:00
End: 10/19/2019 14:00:00
Description: ...FROST ADVISORY REMAINS IN EFFECT UNTIL 10 AM EDT THIS MORNING... * WHAT...Temperatures as low as 33 will result in frost formation. * WHERE...eastern Ohio, southwest Pennsylvania, and northern West Virginia. * WHEN...through 10am Saturday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left ---> Frost Advisory

A Good Example Why Relative Humidity is Bogus

Most folks look at the humidity expressed as a percentage – known as Relative Humidity, or just RH. But, weather nerds and professionals rely on the dew point as a more accurate indicator of atmospheric moisture. This morning’s reading presented a good example of why RH is really a bogus number when it comes to expressing the humidity.

This morning’s air temperature was 57 degrees. The dew point was 56. That made the relative humidity 99%.

Yet, even with the humidity at 99%, it felt refreshing outside and not muggy at all. So, the 99% humidity reading is not really a good indicator of how humid the air is. It’s very pleasant outside.

Dew points are a much better indicator of how humid or uncomfortable the air is. When you use dew points, the air doesn’t start to become noticeably muggy until dew points approach 65°. When dew points get to the 70s, it starts to feel oppressively humid.

That’s why most weather folks express humidity by measuring the dew point and not relative humidity.