Halloween in South Carolina doesn’t always bring crisp air and chilly nights. The state’s humid subtropical climate usually keeps late October warmer than you might expect, especially compared to up north.
Most years, you’ll see daytime highs in the upper 60s to low 70s. Evenings often stay in the 50s.
You’ll notice the weather shifts depending on where you are. Coastal spots like Charleston usually stay milder and more humid.
Inland cities such as Columbia or Greenville tend to cool down faster after sunset. Sometimes a cold front sweeps through, dropping temperatures fast or making Halloween night a bit damp.
These swings in weather shape costume choices and affect how comfortable trick-or-treating feels. If you know what to expect, you can plan to dress light for a warm evening or layer up if a sudden chill sneaks in.
Typical Halloween Temperatures in South Carolina
South Carolina’s humid subtropical climate brings mild to warm afternoons in late October, followed by cooler evenings.
Daytime highs usually feel comfortable for outdoor events, but inland temperatures can drop quickly after sunset.
Average Highs and Lows on October 31
On Halloween, you’ll usually see afternoon highs between 68°F and 75°F across most of the state. Charleston and other coastal areas often stay warmer, while Columbia or Greenville might run a bit cooler.
Nighttime lows typically fall between 48°F and 55°F, though Upstate pockets can dip into the low 40s. Trick-or-treating often starts in mild weather but ends with a real chill.
Here’s a quick look:
| Location | Avg High | Avg Low |
|---|---|---|
| Charleston | 73°F | 55°F |
| Columbia | 71°F | 50°F |
| Greenville | 69°F | 48°F |
So, if you’re heading out after dark, it’s smart to plan for light layers.
Temperature Variability Across Regions
South Carolina’s geography means you’ll see regional differences on Halloween. The coastal plain stays warmer in the evening, thanks to the Atlantic Ocean.
Inland regions like the Piedmont and Upstate cool off faster after sunset. For example, Myrtle Beach might hang in the upper 60s well into the evening, while Greenville can slip into the 40s by night.
The Midlands, including Columbia, usually land somewhere in between.
Humidity plays a part, too. Coastal areas feel stickier, while inland spots get drier and cooler at night. Even when temperatures match, the air can feel very different.
Recent Trends in Halloween Temperatures
Lately, Halloween afternoons in South Carolina have leaned warmer than the long-term averages. Some years, highs reach the upper 70s or even low 80s, especially in the Midlands and along the coast.
Even with those warm afternoons, nights cool off fast. The Upstate still sees chilly evenings in the 40s, while the coast stays milder.
It seems like fall warmth hangs on, but clear skies let things cool down quickly after dark.
Rainfall and Precipitation Patterns on Halloween
Late October in South Carolina often brings mild and dry conditions, but rain can still show up. The timing and amount of rain can change how Halloween feels outside.
Historical Chance of Rain
Records show Halloween in South Carolina is more likely to be dry than wet, though some years bring showers. On average, you’re looking at about a 20–30% chance of measurable rain depending on where you are.
Charleston and other coastal cities have a slightly higher chance, thanks to the ocean. Columbia and Greenville usually see fewer rainy evenings, but a passing cold front can still bring a quick shower.
When rain does fall, it’s usually light. Severe storms are rare on Halloween, but a cold front can bring both rain and a sudden chill.
Typical Rainfall Amounts in Late October
Late October isn’t the wettest time of year for South Carolina. Monthly rainfall averages 2.5 to 3.5 inches statewide, and Halloween comes at the end of that period.
You’re more likely to get a brief shower than a soaking rain. Most Halloween rain totals come in under half an inch. Heavy rain is possible, but it’s not common.
Mountains in the northwest, like Jocassee, usually see more annual rainfall, but even there, late October is pretty moderate compared to summer.
Impact of Rain on Halloween Activities
Rain can definitely change trick-or-treating, festivals, and community events. Light rain might make families cut their time outside short, while heavier showers can move things indoors.
If rain comes with a cold front, you’ll notice cooler air. Damp and windy weather can make the evening feel several degrees colder.
If you’re planning Halloween activities, it’s smart to bring umbrellas or light rain jackets. Having an indoor backup plan helps keep the fun going if weather turns sour.
Evening and Nighttime Weather for Trick or Treating
When you plan for Halloween in South Carolina, evenings usually bring cooler air, early sunsets, and a small chance of rain. These things affect what you wear, how long you stay out, and how comfortable kids feel while trick-or-treating.
Typical Evening Temperatures
By dusk on Halloween, temperatures usually fall into the upper 50s to low 60s across most of South Carolina. The day’s high is around 68°F, but once the sun drops, so do the temps.
Some years swing hotter or colder. One of the warmest Halloweens hit the mid-80s, while one of the coldest dipped into the 30s. Those are outliers, but it shows how unpredictable the season can be.
Most years, you’ll want light jackets, sweaters, or layers for trick-or-treating. Kids in thin costumes may get chilly without an extra layer. If you’re out late, especially past 9 p.m., lows can reach the mid-40s in some places.
Sunset Timing and Daylight Hours
Daylight fades fast in late October. On Halloween, sunset in South Carolina happens around 6:30 to 6:40 p.m. depending on where you are.
Trick-or-treating usually starts during the last bit of daylight and continues after dark.
Earlier sunsets mean cooler air and less visibility. Streets and sidewalks get tricky, especially where lighting is poor. Reflective tape or glow sticks help kids stay visible to drivers.
Since the sun sets before most families finish dinner, you’ll probably spend most of your evening outdoors in the dark. Planning your route ahead of time helps you make the most of the little daylight left.
Weather Preparation Tips for Trick or Treat
You can get ready for Halloween evening by focusing on three things: temperature, visibility, and rain chances.
- Dress kids in layers that are easy to put on or take off.
- Add reflective tape or carry flashlights for safety after dark.
- Check the forecast for rain. The chance of measurable rainfall on Halloween in South Carolina is about 28%, so most years are dry, but you never know.
If showers pop up, they’re usually light and scattered. Toss a small umbrella or poncho in your bag to keep costumes dry. Being flexible with timing and routes keeps trick-or-treating safe and fun, no matter what the weather does.
Influence of Cold Fronts and Sudden Cool Downs
Cold fronts often roll through South Carolina in late October, bringing quick temperature drops and sometimes rain. These changes can shake up your Halloween plans, especially if you expected a mild night but end up with chilly winds or damp sidewalks.
Frequency of Cold Fronts Around Halloween
A cold front moves through the state every few years around Halloween. These systems are pretty common in the Southeast during autumn, as cooler, drier air pushes in from the north.
Sometimes the front comes just before Halloween, leaving behind crisp, dry evenings. Other years, it hits right during trick-or-treat hours, so you get a sudden shift from a warm afternoon.
Daytime highs can still reach the upper 70s or low 80s in late October, but after a front, temperatures often fall into the 50s or 60s. That makes planning outdoor activities a bit of a guessing game.
While it doesn’t happen every year, there’s a good chance a front will influence the holiday. Even dry air can feel colder if it’s breezy.
How Cold Fronts Affect Temperatures and Rain
As a cold front arrives, temperatures usually peak by midday and then drop fast. By evening, you might notice a 15–20 degree swing from the afternoon. Wind chills can make it feel even colder, especially in open spots.
Rain often comes with these fronts. Showers usually start in the afternoon or early evening. They’re often brief, but they can make roads and sidewalks slick, which isn’t great for trick-or-treaters.
The cold snap doesn’t always last long. Usually, the sharp chill sticks around for a day or two before things return to normal. Sometimes the first freeze of the season follows soon after, especially in the Midlands or Upstate.
If you’re planning anything outside, remember a cold front can bring three changes:
- Lower temperatures by evening
- Stronger winds that make it feel colder
- Scattered rain that might show up during peak activity hours
Humidity and the Humid Subtropical Climate
South Carolina’s humid subtropical climate brings warm, moist air for much of the year. By late October, humidity levels drop compared to summer, but the air usually still holds enough moisture to notice during outdoor activities.
Humidity Levels in Late October
Relative humidity in late October typically averages between 65% and 75% across most of South Carolina. Charleston and other coastal spots usually run higher, while Columbia and Greenville tend to be a bit lower.
Mornings feel damper, with readings often above 80%. As the day warms up, humidity drops, sometimes hitting the low 50s in the afternoon. After sunset, things get more humid again.
Dew points in late October are more moderate, usually between 55°F and 65°F. The air doesn’t feel nearly as oppressive as July or August, but you’ll still notice some moisture, especially if you’re outside for a while.
Effects of Humidity on Comfort During Halloween
Humidity directly affects how comfortable you feel on Halloween. Even with mild air in the 60s to low 70s°F, higher humidity can make costumes feel warmer and heavier.
Masks, face paint, or layers can trap heat and moisture, making things uncomfortable.
If you’re walking long routes, you may notice sweat doesn’t evaporate quickly. This can make you feel sticky, especially in coastal areas where nighttime humidity goes up again.
On the bright side, moderate humidity keeps the air from getting too dry, which helps your skin and breathing. Light, breathable fabrics and costumes with some ventilation make a difference in these conditions.
Unusual Weather Events: Freezing Temperatures and Extremes
South Carolina’s Halloween weather doesn’t always stay mild. Some years, a sharp chill sneaks in with freezing nights. Other times, the heat hangs on and makes late October feel more like summer. Both extremes have left their mark on the state’s holiday history.
Historical Freezing Events on Halloween
You probably don’t expect freezing temperatures in South Carolina on October 31, but they do happen. In the Upstate and Midlands, cold snaps have sometimes dragged nighttime lows below 32°F.
These cold events don’t come around often, but when they do, they create icy conditions that can catch outdoor planners off guard. Sometimes, early-season Arctic air masses push into the region before November.
When that happens, you’ll spot frost on lawns and car windshields. Trick-or-treaters might end up grabbing winter coats instead of their usual light costumes.
In the mountains and foothills, freezing nights show up a bit more often. The higher elevation lets cold air settle quickly. Records actually show a few Halloweens have started off in the upper 20s, which really reminds you how fast fall weather can flip.
These cold snaps don’t just bother people—they hit agriculture, too. A hard freeze in late October can really damage things like late-season veggies or flowers. Folks in rural areas might remember years when growers scrambled to cover plants before a surprise cold front rolled in.
Warm Spells and Record Highs
Sometimes, Halloween in South Carolina surprises everyone with record warmth. Afternoon highs can jump into the 80s, especially along the coast or down south.
Warm, humid air drifts in from the Gulf or Atlantic and really cranks up those temperatures. It’s honestly a bit odd to feel that kind of heat this late in the year.
Back in 2012, a big regional heat wave pushed a lot of Upstate and Midlands spots above 100°F earlier that summer. That kind of extreme warmth sometimes just hangs around through the fall.
By late October, it’s not out of the question to get highs way above what you’d expect. That’s just how unpredictable things can get.
When these warm spells hit, you might still see mosquitoes buzzing around. Summer pests don’t exactly get the memo that it’s Halloween.
Costumes meant for chilly weather? They can feel downright stifling. Sometimes, outdoor events feel more like July than the end of October.
Historical records actually show that some years, South Carolina ranked as one of the warmest states in the Southeast during October. If anything, it just proves how quickly the state’s Halloween weather can swing from cold to weirdly hot.