You're standing on the balcony of an oceanfront resort, coffee in hand, looking at the Atlantic. Is it 85 degrees and humid, or are you shivering in a fleece? Honestly, that depends entirely on whether you fell for the "it's always sunny in South Carolina" myth or actually checked the extended Myrtle Beach weather patterns.
Most travelers treat the Grand Strand like a Caribbean island. It isn't. Myrtle Beach is a subtropical coastal city with four distinct personalities, and if you don't time your visit right, you'll end up with a suitcase full of swimsuits during a freeze.
The Winter Gamble: January and February Realities
Let’s get the "off-season" out of the way first. January is the coldest month here. Period. We’re talking average highs of 56°F and lows that hover around 37°F.
Some people think they can swim in the winter. You can't. Unless you’re a polar bear or wearing a 5mm wetsuit, the ocean—averaging 52°F in January—will be physically painful.
But here is the weird part: January is actually quite sunny. According to historical data from the Myrtle Beach International Airport, about half to two-thirds of January days are predominantly clear. You’ll get these beautiful, crisp afternoons where it feels like 65°F in the sun, followed by a night where the frost covers the greens at the Dunes Club.
- The January "Freeze" Swing: It's common to see a 30-degree temperature swing in a single week.
- Precipitation: It doesn’t rain much, but when it does, it's a cold, misty drizzle that lingers.
- Crowds: Non-existent. You can walk into any restaurant in Murrells Inlet without a reservation.
February starts to tease the spring, but it’s a bit of a liar. While the average high bumps up to 59°F, the humidity starts to creep back. It’s a great month for golfers because the courses are empty and the "winter rates" are a steal, but don't expect to lay on the sand.
Spring Fever and the Humidity Wall
March is when the city wakes up. This is also when the extended Myrtle Beach weather becomes a chaotic mix of "Perfect" and "Pollened."
Highs climb into the mid-60s, and by April, you’re hitting a comfortable 73°F. This is arguably the best time to visit if you care about your skin and your sanity. The air is dry, the UV index is manageable (usually around a 6), and the azaleas are screaming with color.
Then comes May.
May is the transition month. The ocean finally hits 70°F, which is "swimmable" for the brave. But more importantly, the humidity begins to stabilize. By late May, you’ll start feeling that thick coastal air that defines South Carolina summers.
The Summer Sizzle: Humidity and Afternoon Booms
If you’re coming in July or August, pack for a sauna.
Average highs hit 91°F, but that number is a lie because of the dew point. In the South, we measure heat by how much you sweat while standing still. With relative humidity often exceeding 70%, the "real feel" is regularly in the triple digits.
Here is the daily rhythm you need to know:
- 10:00 AM: Already hot. The sun is a laser.
- 2:00 PM: The "Heat Wall" hits.
- 4:00 PM: The sky turns black.
- 4:30 PM: A massive thunderstorm rolls in from the west, dumps two inches of rain, and disappears.
- 6:00 PM: Steam rises from the pavement, and the air feels even heavier than before.
July is the wettest month on average, receiving about 5.19 inches of rain. Most of that comes from these localized thunderstorms. They aren't "washouts," so don't cancel your plans. Just plan to be at the swim-up bar or under a roof when the thunder starts.
The Hurricane Elephant in the Room
We have to talk about it. Hurricane season officially runs from June 1st to November 30th.
However, looking at the extended Myrtle Beach weather history, the real danger zone is mid-August through early October. Hurricane Hugo (1989) and Hurricane Florence (2018) are the names that still haunt the locals.
If you are planning a trip in September, get the travel insurance. Honestly. September is actually beautiful—the ocean is at its warmest (81°F) and the crowds drop off—but the risk of a tropical system is at its absolute peak.
Ocean Temperatures at a Glance (The "Can I Swim?" Test)
- March: 57°F (No)
- May: 70°F (Maybe)
- July: 82°F (Yes, it's like a bath)
- September: 81°F (Perfect)
- November: 64°F (Only for the hardcore)
Fall: The Local's Secret
October is the "Goldilocks" month. The humidity vanishes. The highs are a crisp 77°F. The water is still warm enough from the summer heat to dip your toes in, but the air doesn't make you feel like you're breathing through a wet towel.
If you’re looking at an extended Myrtle Beach weather forecast for October, you'll notice it's also the driest time of year. Rainfall drops to around 3.23 inches. It’s perfect for the Blue Crab Festival or just walking the Boardwalk without the summer sweat.
Actionable Tips for Navigating the Forecast
Don't just look at the little sun icon on your phone. Here is how to actually prep for a Myrtle Beach trip based on the climate data:
- Layering is King: If you visit between November and March, you need a windbreaker. The ocean breeze makes 55°F feel like 45°F very quickly.
- The 4 PM Rule: In the summer, don't schedule outdoor photos or weddings for late afternoon. You will get rained on. Stick to 10 AM or sunset.
- Sunscreen is Non-Negotiable: Even in March, the reflection of the sun off the sand and water will fry you. The UV index here is much higher than in the Northeast or Midwest.
- Watch the Dew Point: If the dew point is over 70, you’re going to be miserable outdoors. Look for indoor attractions like Ripley’s Aquarium or the Hollywood Wax Museum during these spikes.
- Hurricane Apps: If traveling in the fall, download the "National Hurricane Center" (NHC) tracker. Local news stations like WMBF are also great for hyper-local storm surges.
Myrtle Beach isn't a "one size fits all" destination. The weather dictates the vibe. You can have a peaceful, chilly retreat in the winter or a high-energy, sweaty beach bash in the summer. Just make sure you know which one you're signing up for.
👉 See also: Why Shedd Aquarium Is Still Chicago’s Most Incredible Experience
Next Steps for Your Trip
Check the current 10-day outlook specifically for "Myrtle Beach International Airport" rather than just "South Carolina," as the ocean temperatures can create a micro-climate that is 5-10 degrees different from just 20 miles inland. If the water temperature is below 68°F, ensure your hotel has a heated indoor pool or a lazy river. For September travelers, verify your hotel's hurricane cancellation policy before the 48-hour window.