Humidifier and headache?

I am sure it is a coincidence but my nose has felt dry lately so 3 nights ago I turned my humidifier up a notch and the dryness went away but I have had a headache both days. I don't ususally have headaches. Any ideas of whether there is a connection?

maybe it was just an earthquake headache because now that the earth upheaved in Peru the headache is gone .... (I also turned the humidifier back down though). hmmmm