That might be because of humidity. But what is humidity? Humidity is a measure of how much water there is in the air. Not liquid waterlike rain, invisible water in the form of a gas called water ...

While absolute humidity is purely a measurement of moisture in the air, relative humidity is the measurement of moisture compared to the amount that can exist at the air's current temperature.

If you want to measure humidity (and temperature, and maybe even barometric pressure) in a device that you’re building, have a look at this comprehensive test of seven different options.

A capacitor type of hygrometer is usually used to measure relative humidity. The sensor has a dielectric polymer layer that absorbs water molecules from the air through a thin metal electrode.

Dew point measures the air’s moisture content directly and impacts weather perception more accurately than relative humidity.