So you're looking at the clemson sc weather forecast and trying to figure out if you need a heavy parka or just a light hoodie for that walk across Bowman Field. Honestly, Clemson weather is a bit of a mood. One minute you're soaking up sun by the reflection pond, and the next, a damp chill rolls off Lake Hartwell that catches you completely off guard.
It’s Tuesday, January 13, 2026. Right now, it's actually pretty decent out there. We’re looking at a current temperature of 57°F. The sky is mostly sunny, and there’s a light breeze coming out of the southwest at about 8 mph. It feels like one of those classic "false spring" days we get in the Upstate, but don't let that fool you into thinking winter is over.
Today's Reality Check
If you’re heading out for the afternoon, it’s going to stay pleasant. The high is pegged at 59°F. That’s a few degrees warmer than the historical average for mid-January, which usually sits closer to 54°F. But here is the kicker: the humidity is sitting at a crisp 32% right now, though the daily average will hover around 55%.
As the sun dips, things change fast. Tonight, the low is going to bottom out at 29°F. That is a 30-degree swing. If you leave your house in a t-shirt because it feels like 60 at 2:00 PM, you are going to be miserable by 8:00 PM. The clouds will move in tonight, and while there’s a tiny 10% chance of a stray shower, it's mostly just going to be a cold, gray night.
The Lake Hartwell Factor
People who aren't from around here don't realize how much the water dictates the clemson sc weather forecast. Clemson is basically wrapped in Lake Hartwell. This giant body of water acts like a thermal battery. In the early winter, it stays a bit warmer than the air, sometimes creating these weird local mists or keeping the immediate shoreline just a degree or two above freezing while the rest of the county is icing over.
On the flip side, once that water gets cold in late January and February, it keeps the air damp. A 40-degree day in Clemson feels significantly colder than a 40-degree day in a drier climate. It’s that "wet cold" that gets into your bones.
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January Patterns and The Mountains
We are nestled right in the foothills of the Blue Ridge Mountains. This is a blessing for our winter forecast. The mountains to our northwest often act as a shield, blocking the most brutal arctic air masses before they can dump down into the Piedmont.
- Average Highs: Usually around 54°F.
- Average Lows: Typically hover near 34°F.
- Snow Reality: Everyone asks about snow. Historically, Clemson only sees about two inches of snow per year. We’re much more likely to get "wintry mix"—which is just a polite way of saying freezing rain that turns the hills into a skating rink.
According to data from the South Carolina State Climatology Office, January is statistically one of the cloudiest months for us. About 49% of the time, the sky is overcast. Today being mostly sunny is actually a bit of a treat.
Clemson SC Weather Forecast: Survival Guide
If you're visiting or just moved here, forget the big bulky coat unless you're standing still for a three-hour football game. The secret is layers.
- The Base: A standard t-shirt or long-sleeve.
- The Insulation: A fleece or a "down sweater" (those thin puffy jackets).
- The Shell: Something windproof. Those southwest winds at 10 mph today might not sound like much, but they'll cut right through a knitted sweater.
The UV index today is a 3. It's low, but if you're out on the lake all day, you can still get a bit of a burn because the sun reflects off the water. Don't be that person with a January sunburn.
What to Expect This Week
While today is clear with 0% precipitation, the clouds coming in tonight are a precursor to the standard Upstate winter rhythm. We tend to cycle through three days of "beautiful and crisp" followed by two days of "gray and drizzly."
Check the barometer too. It's currently around 30.13 "Hg. When that starts to drop, you know the pressure system is shifting. In this part of South Carolina, rain usually isn't a quick afternoon thunderstorm like we get in July. In January, it's often a slow, steady soak that lasts for twelve hours.
Actionable Weather Advice
Stop relying on the generic weather app that uses a sensor thirty miles away in Greenville. Use the Clemson University WeatherSTEM station if you want to know exactly what’s happening on campus.
For tonight: if you have outdoor plants, bring them in or cover them. We are hitting 29°F, which is a hard freeze. If you're driving early tomorrow morning, watch for "black ice" on the bridges over Lake Hartwell. Even if it didn't rain, the humidity (currently 32% but rising to 55%+) can condense and freeze on cold bridge surfaces.
Check your tire pressure. These 30-degree temperature swings cause your PSI to fluctuate wildly. If your "low tire" light came on this morning when it was 30 degrees, it’ll probably turn off by lunch when it hits 57. But it’s a good reminder that winter is definitely here.