Lets say you get in the woods for a morning hunt. You get set up on the lower end of a hill side. The sun has risen and the dark woods start to lighten up. The first thing you do is check the wind with a puff bottle. The air is relatively calm on this morning, but the powder drifts down the hill and to your right. You already know that the deer are likely behind you at this time, in a field and slowly coming your way to feed on the acorns that lie below the hill. At this point you give out a rattling sequence to them. Knowing that any approaching deer will probably try to wind you, you patiently look down the hill for any movement. Suddenly, you hear two loud stomps behind you. It’s the sound no hunter forgets, the sound of an alert deer stomping the ground. You want to turn around to look but you know he’s looking right at you. Seconds later the deer blows and runs off into cover. You immediately grab your puffer bottle and squeeze it to find that your scent shifted in the opposite direction. Understanding thermals and how it affects deer hunting can help prevent mishaps such as these.
In the morning, cool air is warmed as the sun rises. This warm air becomes less dense and begins to rise. In fairly calm wind conditions, this can cause your scent to shift in another direction, especially when on a hill side or down in a bottom or ravine. Evening hunts can have the opposite affect. As air cools from the sun lowering in the sky, air becomes more dense and sinks lower. One way to counteract this is to get set up high during morning hunts, and low during evening hunts.
Periodically check the wind throughout your hunts under different wind directions, speeds, and conditions to learn how this may affect your stands that are in hilly areas. Understanding thermals and how it affects deer hunting is a great tool to add to your scent control methods.