Quiz: Which of these would feel more humid?
- 100° F at 32% relative humidity
- 62° F at 70% relative humidity
Leading question alert: it’s #1.
Unless you understand the relationship between temperature and relative humidity (explained well in this video
), understanding how humid it feels
is hard to pinpoint.
The dew point is the temperature the air needs to be cooled to (at constant pressure) in order to achieve a relative humidity (RH) of 100%. At this point the air cannot hold more water in the gas form. If the air were to be cooled even more, water vapor would have to come out of the atmosphere in the liquid form, usually as fog or precipitation.
So cool, I barely understood that either, but the tl;dr is: dew point is the measure for how humid it feels, which is all anyone really cares about.
So when deciding what to pack, look at the forecasted dew point at your destination instead of humidity. If the dew point is <60° F, you’re looking 😎.
Here is a handy cheat sheet: