One word comes to mind when one thinks about Southern climate: hot. That’s the first word that occurs to Southerners as well, but virtually every survey of why residents are attracted to the area puts the climate at the top of the list. Go figure.
How hot is hot? The average high for July, the region’s hottest month, in Savannah  is about 92°F, in Charleston  about 89°F. While that’s nothing compared to Tucson or Death Valley, coupled with the region’s notoriously high humidity it can have an altogether miserable effect.
Heat aside, there’s no doubt that one of the most difficult things for an outsider to adjust to in the South is the humidity. The average annual humidity in Charleston and Savannah is about 55 percent in the afternoons and a whopping 85 percent in the mornings. The most humid months are August and September.
There is no real antidote to humidity—other than air conditioning, that is—though many film crews and other outside workers swear by the use of Sea Breeze astringent. If you and your traveling partner can deal with the strong minty odor, dampen a hand towel with the astringent, drape it across the back of your neck and go about your business.
Don’t assume that because it’s humid you shouldn’t drink fluids. Just as in any hot climate, you should drink lots of water if you’re going to be out in the Southern heat.
August and September are by far the wettest months in terms of rainfall, with averages well over six inches for each of those months. July is also quite wet, coming in at over five inches on average.
Winters here are pretty mild, but can seem much colder than they actually are because of the dampness in the air. The coldest month is January, with about a 58°F high for the month and a 42°F average low.
You’re highly unlikely to encounter snow in the area, and if you do it will likely only be skimpy flurries that a resident of the Great Lakes region wouldn’t even notice as snow. But don’t let this lull you into a false sense of security. If such a tiny flurry were to hit, be aware that most people down here have no clue how to drive in rough weather and will not be prepared for even such a small amount of snowfall. Visitors from snow country are often surprised, sometimes bordering on shock, by how completely a Southern city will shut down when that once-in-a-decade few millimeters of snow finally hits.
The major weather phenomenon for residents and visitors alike is the mighty hurricane. These massive storms, with counterclockwise-rotating bands of clouds and winds pushing 200 miles per hour, are an ever-present danger to the southeast coast June–November of each year.
While the South Carolina coast has had its share of hurricane strikes, historically the Georgia coast has been relatively safe, if not immune, from major hurricane activity. In fact, as of this writing the last major storm to directly hit the Georgia coast was in 1898. Meteorologists chalk this up to the Georgia coast’s relatively sheltered, concave position relative to the rest of the southeastern coastline, as well as prevailing pressure and wind patterns that tend to deflect the oncoming storms.
In any case, as most everyone is aware now from the horrific, well-documented damage from such killer storms as Hugo, Andrew, and Katrina, hurricanes are not to be trifled with. Old-fashioned, drunken “hurricane parties” are a thing of the past for the most part, the images of cataclysmic destruction everyone has seen on TV having long since eliminated any lingering romanticism about riding out the storm.
Tornadoes—especially those that come in the “back door” through the Gulf of Mexico and overland to the Georgia or Carolina coast—are a very present danger with hurricanes. As hurricanes die out overland, they can spawn literally dozens of tornadoes, which in many cases prove more destructive than the hurricanes that spawned them.
Local TV, websites, and print media can be counted on to give more than ample warning in the event a hurricane is approaching the area during your visit. Whatever you do, do not discount the warnings. It’s not worth it. If the locals are preparing to leave, you should too.
Typically when a storm is likely to hit the area, there will first be a suggested evacuation. But if authorities determine there’s an overwhelming likelihood of imminent hurricane damage, they will issue a mandatory evacuation order. What this means in practice is that if you do choose to stay behind, you cannot count on any type of emergency services or help whatsoever.
Generally speaking, the most lethal element of a hurricane is not the wind but the storm surge, the wall of ocean water that the winds drive before them onto the coast. During Hurricane Hugo, Charleston’s Battery  was inundated with a storm surge of over 12 feet, with an amazing 20 feet reported farther north at Cape Romain.
In the wake of such devastation, local governments have dramatically improved their once tepid disaster-response plans. For example, the large red traffic barriers you see stowed in their ready positions at many exits along I-16 in Georgia are a direct result of the chaos of the botched evacuation during Hurricane Floyd in 1999. Learning from that lesson, Georgia officials decided to make all four lanes of I-16 westbound in the event of a major evacuation, and those red barriers are there today to reroute traffic should they ever be needed.