Charleston Weather Blog

Forecast explanations, atmospheric science, and other cool weather-related stuff for Charleston, SC

Rest of the work week: Dangerous heat builds

/ at 9:00 PM

The weather story for the rest of the work week will be the intensifying heat wave across the area as high pressure building in aloft continues to strengthen, while southwesterly winds continue to pump in high-dewpoint air that will send heat indices over 110° in spots.

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Tuesday: Heat starts to turn up

/ August 10, 2026 at 9:29 PM

It’s a very toasty start to the school year for Charleston County on Tuesday as this week’s heat wave will begin in earnest as high pressure aloft takes hold. We’ll start the day on a very mild note, with lows in the mid-to-upper 70s warming to the mid-90s in the afternoon. Dewpoints will run in the low-to-mid-70s inland, while closer to the coast, they’ll run in the upper 70s. That will help drive heat indices solidly into the 100s, with the highest heat indices expected in the Highway 17 corridor and points east. A Heat Advisory will be in effect for Charleston County and the southern part of Berkeley County from 11am-8pm, when heat indices should exceed 108° and could top out near 111° as the seabreeze pushes by. The aforementioned high pressure will make it much harder for thunderstorms to develop, though a couple popup showers will be possible. With that in mind, though, don’t count on thunderstorms to impart any relief from the heat.

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The week ahead: High heat returns; heat advisories possible

/ August 9, 2026 at 9:07 PM

The main weather story this week will be the return of heat that will be reminiscent of what we experienced earlier in July, with another round of dangerous heat indices pushing 110-115° at times.

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