Travel Nut here (Mr TTR & I are semi-retired and we travel a lot)
January is the coldest month in the Northern Hemisphere… depending how cold and where, depends on how low the Jet Stream dips. The lower it goes, the more the cold air is pulled further south into the USA.
So you could see for example States like Florida in the deep south getting temps anywhere from a low of below freezing (in the 20s) to a high in the 90s F
For relatively decent weather in January (40s and above) you want to be as far south as the Carolinas.
Mr TTR & I have vacationed in January in some of the following States…
North Carolina – South Carolina – Georgia – Mississippi – Louisiana – Alabama – and Florida.
They are all great Destinations, with much to see and do, just be aware that the weather can be unpredictable.
WE LOVE places like… Raleigh NC – Myrtle Beach – Charleston SC – Savannah – New Orleans – ALL of Florida including… Pensacola & the Panhandle – St Augustine – Daytona Beach – Orlando – Tampa – Clearwater – St Pete Beach – Fort Meyers – Aligator Alley – Fort Lauderdale – Miami – and ALL of The Keys !!
Florida is amazing to explore, and a very large state. We love doing a road trip there, just driving from place to place to see what makes everyone different from the next.
The one place we’ve always been lucky is The Florida Keys… Historical Weather Stats will tell you that it has never gone below Freezing there. And due to its extreme southerly location (Key West is the most Southerly Point in the Continental USA at Latitude 24.33 Degree North)… this is one spot that just about ALWAYS has amazing HOT Weather…
Mr TTR & I have gone several times in January, and the temps are typically in the 70s, 80s, or 90s during the daytime.
The Keys is like a wee bit of the Caribbean in the USA… many of the benefits without a lot of the hassle. No Passport required, same language, currency, Food, Restaurants, Hotels, Stores you are familiar with etc
If you want more info on The Keys you can ask me here… or send me a PM
Weather also can be iffy in the “Northern Caribbean” in January. Cooler temps and wind.
So not the best time to visit the islands of the Greater Antilles… islands like Bermuda, Bahamas, Cuba, Puerto Rico or the coast Mexico if you want to be guaranteed good weather.
You really have to get as far southeast in the Caribbean before you’ll see a marked increase in temp if the Jet Stream is lying low.
The best weather in January will be found further to the East & South (The Lesser Antilles) and the coast of South America if you want to be guaranteed good weather.
Wikipedia – Antilles = http://en.wikipedia.org/wiki/Antilles