There have been a number of studies done on deer activity in relation to the weather. Deer in different areas can stand hotter or colder weather than deer in other areas.

T.R.Michels has some interesting graphs on deersightings in relation to the temperature and wind. You can view them on his site by Googling "Deer Activity Graphs". Hehas spent over 10 years reserching deer.

I've learned that when it is too hot or too cold for deer movement in the states I hunt, I may not see normal deer movement, in which case I go looking for the deer where it is eitherwarmer, less windy, drier or cooler - where the deer may be found.