Veiled:
day basking spot 96.5F/36C
day cooler spot / ambient range 70-80F/21 -26C
night to a low of 60F/15.5C
Panther:
Humidity: from lows of 45% to as much as 90% when misting (aim for 60%+ and ensure the chameleon has plenty to drink)
day basking spot 90F/32C
day cooler spot / ambient range 70-80F /21 -26C
night to a low of 65F/18C
A ten degree drop in temp from daytime ambient night ambient is desireable.
Despite the fact that chameleons both in the wild and in captivity tolerate temperatures of lower the 65F/18C at night, I would suggest not going any lower than 65F/18C, and there are a few people who feel strongly that you should keep the night low at 70F/21C. From Chameleons Online E-Zine: "...Fact: Chameleons prefer (and typically require) a temperature drop at night. This drop should be at least 10º-15º F for most of the commonly held species (i.e., jacksonii, pardalis, calyptratus, dilepis and gracilis). These species can easily tolerate night time temperatures into the 60s and often much lower as long as they can warm up during the day. ...
Dr. Ed Pollak, Ph.D.
I have a male panther. House humidity in Winter rarely gets over 40%. He does fine with this. I just make sure he has plenty to drink and well hydrated prey.