Charleston Heat Index Today
Updated planning preview · 11:00 PM forecast from WeatherAPI
Heat index
78°F
Low
Routine outdoor plans are generally reasonable.
Temperature
73°F
Humidity
95%
Estimated WBGT
22.6°C
UV index
0.0
Best outdoor window
8:00 AM–12:00 PM
Lowest combined heat and UV load in the available hourly preview.
Hourly heat risk
WBGT values are labeled as modeled estimates until a provider supplies measured readings.
| Time | Temperature | Heat index | Estimated WBGT | UV | Risk |
|---|---|---|---|---|---|
| 8 AM | 69°F | 69°F | 22.3°C | 0.0 | Low |
| 10 AM | 69°F | 69°F | 22.2°C | 0.1 | Low |
| 12 PM | 69°F | 69°F | 22.1°C | 0.7 | Low |
| 2 PM | 69°F | 69°F | 22.1°C | 0.9 | Low |
| 4 PM | 70°F | 75°F | 22.2°C | 0.4 | Low |
| 6 PM | 70°F | 70°F | 22.0°C | 0.1 | Low |
| 9 AM | 71°F | 76°F | 21.8°C | 0.4 | Low |
| 11 AM | 76°F | 78°F | 22.5°C | 3.1 | Low |
Today's outlook
In Charleston, the highest modeled heat burden in this preview occurs around 11:00 AM. The recommended window is selected from the lowest combined risk score, temperature, and UV—not from generic city copy.
Three-day forecast
Sunday
Heat index up to 89°F
83°F / 73°F
ModerateMonday
Heat index up to 77°F
73°F / 69°F
LowTuesday
Heat index up to 80°F
78°F / 68°F
ModerateToday in Charleston
What changes across the day
Based on the available hourly WeatherAPI forecast
Peak heat index
78°F at 11:00 AM
The preview low is 69°F around 12:00 PM.
Feels-like difference
4°F above air temp
Current humidity is 95%, one input that changes evaporative cooling.
Peak UV
3.1 at 11:00 AM
UV and heat are separate hazards; the lowest-heat hour may still need sun protection.
Tomorrow's direction
11°F cooler tomorrow
Today's forecast range is 73°F–83°F.
Where these numbers come from
WeatherAPI supplies the forecast. HeatGuard calculates heat-index risk and models WBGT from forecast temperature, humidity and a daytime solar allowance. Modeled WBGT is not an on-site globe-thermometer reading.
Local planning context
Planning for heat in Charleston, SC
Charleston can combine high humidity with warm mornings and evenings. Humidity may keep the heat index elevated even when air temperature alone looks manageable, so compare the full hourly window before choosing a start time.
Forecasts describe outdoor conditions, not an individual's medical risk. Workload, duration, shade, clothing, acclimatization and health can change the appropriate decision.
Nearby forecasts
Keep planning
Track Charleston in HeatGuard
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