I have noted that in the warmer temperatures, there is a slight difference where the projectile hits on the target. This is more so when shooting sabots over the roundball and conicals. Also when it is hot outside the barrel of your rifle will heat up faster and stay hotter longer which seems to effect accuracy and loading.

For this reason I do very little fine tuning of a rifle. Especially where it involves filing down sights. I wait until the temperatures are at least in the 60's before I get too concerned. And it is finally getting cooler here....