SAVANNAH, Ga. (WSAV) – Once again, we are dealing with dangerous heat.

A heat advisory has been issued and continues until 7 p.m. Tuesday evening when temperatures finally begin to slightly cool off. Heat index values yesterday soared as high as 116 degrees.

If you have to be outside this week, standing in the shade can be important on a super hot day because it gives your body a break from the heat and allows it to cool down.

Is there that big of a temperature difference between the shade and the sunshine?

I tested this out today by using our Storm Team 3 handheld weather station. The thermometer will tell me the temperature and heat index both in the shade and in direct sunlight.

SHADE VS SUNLIGHT

Temperatures in the Shade and Direct Sunlight
Heat Index Temperatures in the Shade and Direct Sunlight

What a difference! This is why we stress that you need to take frequent breaks from the sun. A lot of the time, you might not even think about the temperature in the sun feeling so much hotter compared to the actual temperature.  

SCIENCE

Why does it feel “cooler” in the shade?

The shade doesn’t make temperatures cooler. This is all because the temperature you feel in the shade is the actual air temperature.

Being in direct sunlight can make the air feel 10-15 degrees warmer than it actually is because of the sun’s rays touching your skin. Air temperature is always measured in the shade because, in the shade, the thermometer is measuring the actual air temperature and only the air temperature.

A thermometer placed in the sun measures the air temperature PLUS the temperature that the sun heats the thermometer to. That number reading is inaccurate and can be multiple degrees higher than the true air temperature.