June 23, 2011
I've often been asked the question: can temperature affect a deer's sense of smell?
Both temperature and humidity (even more so) have an affect on a deer's ability to smell. On warm days, you can see the heat waves rising. Scent rises with them, so that makes it harder for the deer to smell you on very warm days because your scent is being carried up into the air. I have also seen situations in the late season when it is bitter cold and the air is very dry where deer have trouble scenting, too.
This is because the scent molecules have to stick to the deer's nose and then breakdown to form a chemical reaction with the epithelium in the nose for them to smell. When it is very dry, their nose dries out and the molecules don't stick as well. That is why some days you will see them lick their nose when they are trying hard to smell something.
I don't know that you can actually put this information to work for you in the woods (because even when slightly impaired, their sense of smell is still very formidable), but you still have to play the wind. It may at least make for some interesting conversation at deer camp.