What Does Humidity Mean?
Humidity is the amount of water vapor present in the atmosphere or a confined space. A higher level of humidity indicates a greater level of water vapor. A high humidity level results in a higher dew point temperature. This means that condensation will occur even at high temperatures if the humidity level is high enough.
Humidity can have a profound effect on corrosion in many ways. For example, it can make coating a material with a waterborne coating difficult. A humid environment prevents a waterborne coating from drying rapidly. Blushing (water spotting) can occur on epoxy coatings as well.
Another way that humidity relates to corrosion is that it increases the likelihood of condensation. When condensation forms on an unprotected material the liquid water can serve as an electrolytic solution that enables the corrosive process.