For the most part, the best viewing conditions will be found across the southern and western United States. The Rocky Mountains and parts of western Oregon and Washington are the exceptions there.
The Midwest and Northeast will have some unfortunate timing. "An Alberta Clipper storm will spread clouds and some snow across the Midwest and northern Plains," Accuweather notes, "resulting in poor viewing conditions." However, the site notes that stargazers in the Northeast should get some reprieve with cloud cover having breaks where you can take in the show.
This year's Geminids is well-timed. The moon won't be bright and obstruct your view like it did last year. Additionally, the shower is easier to see than some others. "They're famous for a lot of fireballs," Cooke says. "They're often described as bluish or greenish in color." That should help make the celestial show a little easier to see if you're competing with a little cloud cover or light pollution.