So I can change the temperature outside by walking outdoors with a thermometer? Sorry, I'm not buying it.
Sure going outside changes the temperature. I'm assuming you're warmer than the atmosphere. You are therefore lsoing heat to the atmosphere. Just because the average increase in temperature of the atmopshere is a very slight fraction above zero, doesn't mean it is zero.

The fact that I can change the behavior of matter in a way that defies the rules of physics, merely by exercising my own consciousness, pretty much proves that I am God.
You're not defying phsyics, merely observing it.