If a surface is glossy, applying a primer or sanding might be necessary," Lisa Allardi, owner of CertaPro Painters of Roanoke, says. Follow the additional advice below to ensure your exterior painting project turns out just as good as if you were painting on a warm spring day. With this in mind, you need to be aware of regional climate conditions to properly plan and prepare your exterior painting project. "We start tackling exterior home projects again in Colorado in March or April, when temperatures are more favorable for paint application." "Generally, December, January, and February are the coldest months, and we tend to do less exterior painting during these times, choosing to wait until spring," expresses Allardi.