Just as an aside to the excellent answers already given, please keep in mind that in science, careful language in asking a question can be very important. Your question as stated ignores the precise meaning of the word "humildity" and uses a careless English language meaning of something like "detectable moisture". There is ALWAYS humidity, everywhere. The question is just, "how much", which is why jixxizix said "increasing" not "creating". His post, by the way, is also somewhat careless in that he states that it "increases the relative humidity", which is correct but it would be even more correct to say that it "increases the humidity", meaning that it increases the relative humidity AND the absolute humidity.Is this a way to "humidify" your house? Will boiling water create humidity?
Relative humidity is the amount of moisture in the air relative to the amount of moisture the air can hold at a given temperature. Hot air can hold more moisture, cold air less. Relative humility is how humble you are at a given temp and humidity level. Some people sweat more and lose their humility when overheated and sweaty.It is humidity high enough to humiliate.