A strong cold front is on the way to through southeast so you know what that means: Elsa and Game of Throne memes, the Choir of the Church of the Dripping Pipes is in full chorus, and hospital ER’s will fill with people who tried to bring in cats who really do love the warmth and shelter but have to slash you on principle because they are cats. So when is cold really cold, and what to do about it?
As of this morning, all of Coastal GA and the Lowcountry of South Carolina (better known as the Frogmore Metroplex) are under watches and advisories for Sunday night through Tuesday (14-16 December 2025). It’s important to realize that the various National Weather Service (NWS) offices have different criteria for different parts of the country, even in the same region. For example, here in the Metroplex, a ‘Cold Weather Advisory” is when the wind chill is 20F or below. Extreme Cold is when the wind chill is 10F or lower. But in Florida it’s 25F and 15F respectively, whereas in the north GA and SC mountains and foothills (Greenville-Spartanburg) the criteria is 5F for “Cold” and -5F (minus 5!) to be considered “Extreme Cold!” That’s because the people and infrastructure are of course adapted to the averages. Houses in the deep south are not as well insulated, and while many of the people do seem to have a lot of insulation, they aren’t used to lower temperatures and don’t have heavy jackets, etc.
Also remember that a “watch” is when something is expected in 36-48 hours, and a “warning” is when something is likely within 24 hours.
NWS likes to use the “four P’s:” People, Pets, Pipes, and Plants. Starting with the most important, pets, they need to be inside or in shelter of some kind if the temperatures are going below freezing, especially into the 20’s. Water bowls will freeze over, and they aren’t any more used to it than you are.
Plants: Those that are delicate and can’t move should be covered – do it before the temperatures drop (in this case Sunday afternoon) to retain some heat. Be aware that some plants who can normally survive if in the ground won’t make it if it pots because in a pot their roots might freeze, but in the ground (which of course stays warmer, especially below a couple inches) would be fine. Otherwise, bring them in so your cat can play with them and chase the lizard who was hiding in the pot across your dining room table, knocking off the most expensive items.
So what about pipes? Here is another of those “it depends” situation. There is a huge amount of contradictory advice on dripping water faucets. Why do you need to do it anyway? Because water is weird: unlike most substances, it expands when it freezes. So when in a confined space like a pipe, it can expand until the container bursts. Then when it thaws out, you’ve got a problem.
There is no hard and fast rule. Southern Living has some advice that seems reasonable. Note that some sources (like Angie’s List) have some errors – for example, they say you don’t need to drip the hot water lines when in fact in many homes in the South the hot water tanks are in unheated attics, and the feed lines are not always insulated, so you need to have the hot water side doing a gentle trickle as well (slow drips might not be enough, but it doesn’t need to be full blast either). A key aspect is duration and “cold soaking.” For pipes in or connected to a house, or coming out of the ground, it takes time for the cold to “soak in” (the technical term is thermal inertia). A good rule of thumb is that if the temperatures are below freezing for more than 6 hours, or below 30 for 4 hours, it’s probably smart to drip or drain uninsulated pipes. For Savannah, temps look to go below freezing by Midnight Sunday night, and not recover until 9am or so, with at least five hours of air temperature below 30F (and wind chills will be below 30 from 10pm until almost noon).
As for people, use some common sense. Dress in layers, check on anyone who is vulnerable. Fortunately this isn’t an ice event but if it was you’d need to be ready for power outages and potential isolation for a couple of days if travel was dangerous. In this case, it’s going to be “cold” all day Monday.
So, take cold seriously, and don’t worry that “cold” in Frogmore is a spring T-shirt day in Minnesota or Maine (or even the North Georgia Mountains).
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I am skeptical of early season cold predictions in this part of the country, so I am making a prediction that we may not see temperatures below freezing, or if so only briefly. My reasons: 1. there is a lot of heat in the ground as well as the waters of the Atlantic and
Gulf. 2. The center of the low is far to the northeast, tending to make the southern tail slide more to the east instead of bringing the cold air straight down from the northwest. That said I will take precautions, just in case.
The latest runs of all of the models support a significant below freezing event for the Savannah area, and given we had a surprise several-hours-below-freezing event a few days ago (forecast busted by 8 degrees too high), I’m inclined to give this one some credence. Now, the extent and timing are possibly debatable. GFS is only showing Sun-Mon night below freezing in Savannah, hires models are colder. The NBM is what I quoted above..