Are January and February good months to repot evergreen bonsai Juniper. This would be my first time repotting it and the plant is doing great so far, but I don't want to kill it: I want to make sure that I do it at the right time of year.
In winter around the end just before spring is a very good time to repot your bonsai. Repotting at this time can make space for the roots' growth in spring.
It depends on what part of the world you are located. I live in pacific northwest in Washington state. We have pretty mild winters here in the Puget Sound so I am able to repot my juniper starting in early to mid February. I will give them extra protection from frost and wind until they are re-established in their new pots.