I have a question on breaking in new 2 stroke and 4 stroke engines. Doe's the temperature and humidity effect break in on these engines? Thanks for your advise.

Not so much. The engine's tuning will change a bit with the temperature and humidity, but the overall break-in process won't change. I wouldn't necessarily recommend trying to break in a brand new engine in weather below 50 degrees Farenheit or so. Brand new engines can be a bit stubborn to start, and the cold weather will only increase any difficulties when starting. You won't hurt anything by trying, however.