"The ideal temperature for the light hours is 68 to 78 degrees fahrenheit and for the dark hours there should be about a 15 degree drop in temperature. The growing room should be relatively dry if possible. What you want is a resinous coating on the leaves and to get the plant to do this, you must convince it that it needs the resinous coating on its leaves to protect itself from drying out. In an extremely humid room, the plants develop wide leaves and do not produce as much resin."
while this logic is sound, i wouldnt worry if your temps dont drop 15 degrees at dark time. but they prob will if your using anything other than CFLs