Don't underestimate the effect of even moderately hot & moderately humid air. As air gets warmer, it's ability to hold moisture increases exponentially. 80degree air w/ a RH of 60% (not unusual for the midwest. I live in northern WI & this is not uncommon) has a dewpoint of about 65degrees. If you have a vented crawlspace in an area with a ground temperature of 65 or less, condensation is an issue. 85 degree air w/ rh of 70% - dewpoint is about 74 degrees. I've been in crawlspaces that were water is running down the concrete foundation.
By far the best solution in all cases is prevention.
You can find information on humidity & it's properties by doing a search on "Psychometrics" (not to be confused with psychotic, although it has been suggested that I look into that).