Dangerously high heat and humidity will affect parts of South Carolina’s Lowcountry through Friday evening, with sustained heat-index values that are expected to reach levels that can cause heat illness in a short period. Local authorities have issued an Extreme Heat Warning for some coastal counties and Heat Advisories for surrounding areas as the region prepares for the hottest conditions of the week.
What the alerts cover
An Extreme Heat Warning is in force for Berkeley, Charleston, Beaufort and coastal Colleton counties through late Friday evening. In those areas, heat-index values are forecast to climb above 105°F before noon, with most of the afternoon and early evening expected to feel like 113–120°F.
Nearby Lowcountry counties are under a Heat Advisory, where peak heat-index values are anticipated to reach 105–112°F. Actual air temperatures are expected to be in the lower to mid 90s along the coast and the mid to upper 90s inland on Friday.
| Alert | Counties | Forecast heat-index |
|---|---|---|
| Extreme Heat Warning | Berkeley, Charleston, Beaufort, coastal Colleton | 113–120°F feels-like (rising above 105°F by late morning) |
| Heat Advisory | Other Lowcountry counties | 105–112°F feels-like |
Health risks and practical advice
Heat indices in this range significantly increase the risk of heat-related illnesses, including heat exhaustion and heatstroke, particularly for older people, young children, those with pre-existing health conditions, and anyone performing strenuous work outdoors.
Officials advise the public to take the following precautions:
- Limit strenuous outdoor activity to the coolest parts of the day — early morning or late evening.
- Wear light-coloured, loose-fitting clothing and take frequent breaks in the shade or a cool place.
- Stay well hydrated and avoid alcohol or heavy meals before exertion.
- Never leave people or animals unattended in a hot car.
- Check on elderly neighbours and friends, and keep pets indoors with plenty of cold water.
These are standard, evidence-based precautions for extreme-heat events; they reduce the risk of dehydration and heat-related emergencies. Community cooling centres and air-conditioned public spaces can be lifesaving for those without access to cool environments.
Rain and storm chances
Widely scattered showers and thunderstorms are expected on Friday, mainly in the late afternoon and evening. Not everyone will experience rain, but where storms do form they may bring very heavy rainfall, frequent lightning and strong winds, creating localised hazards such as flash flooding or downed branches. The presence of storms can briefly lower temperatures where they occur, but they also carry added risks for anyone outdoors.
Forecast confidence is moderate: the timing and spatial distribution of storms is difficult to pin down far in advance, so some areas may see relief while others will remain hot and dry until late in the day.
Outlook beyond Friday
Temperatures are expected to stay warm over the weekend, with highs returning to the mid 90s. Another surge of even hotter weather — with upper 90s or possibly low 100s — is forecast for early next week, presenting the potential for a renewed period of widespread heat stress across the region.
The National Hurricane Center is also monitoring two tropical disturbances in the eastern Atlantic, labelled Invest 92L and Invest 94L. These are tropical waves being investigated for development; they do not have an immediate bearing on the South Carolina heat event but are being tracked for potential future impacts.
Where you are in the Lowcountry will determine how intense the heat feels. Stay informed with local weather alerts and follow public-health guidance. If you must be outside, plan carefully, take regular breaks, and make hydration and shade a priority.
