One thing to consider. Some of the new rangefinders and rangefinder binos, with ballistic software in them automatically take many of these atmospheric conditions into account.Along with angle change ect. I have found the information that my leica HD b s gives me in mils has been spot on from below zero to hot summer temperatures. I still have a range card, but don't use it. I dial what my binos tell me. I have only shot to 800 with it,generally concentrating on shots from 500 to 600 for 1 shot kills on coyotes.