An extreme heat index of up to 109 is expected Thursday, July 4, in central and parts of north Georgia.  The high heat is expected to continue through the weekend.

The National Weather Service issued a heat advisory for Cobb County and other parts of the region for Thursday, covering from 1 p.m. to 7 p.m.

What is the heat index?

The NWS defines the heat index as follows on its website:

The heat index, also known as the apparent temperature, is what the temperature feels like to the human body when relative humidity is combined with the air temperature. This has important considerations for the human body’s comfort. When the body gets too hot, it begins to perspire or sweat to cool itself off.

Chart from NOAA showing relationship between relative humidity and temperature in heat index

What is in the heat advisory?

Here is an excerpt from the hazardous weather outlook:

…HEAT ADVISORY IN EFFECT FROM 1 PM TO 7 PM EDT THURSDAY…

* WHAT…Heat index values up to 109 expected.

* WHERE…Portions of central and northwest Georgia.

* WHEN…From 1 PM to 7 PM EDT Thursday.

* IMPACTS…Hot temperatures and high humidity may cause heat

  illnesses.

* ADDITIONAL DETAILS…Hot weather is expected to continue into the

  weekend. Additional Heat Advisories may be needed.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

Drink plenty of fluids, stay in an air-conditioned room, stay out of

the sun, and check up on relatives and neighbors.

Take extra precautions when outside. Wear lightweight and loose

fitting clothing. Try to limit strenuous activities to early morning

or evening. Take action when you see symptoms of heat exhaustion and

heat stroke.

To reduce risk during outdoor work, schedule frequent rest breaks in

shaded or air conditioned environments. Anyone overcome by heat

should be moved to a cool and shaded location. Heat stroke is an

emergency! Call 9 1 1.

What counties are affected in the hazardous weather outlook?

The following counties are listed in the outlook:

Banks, Barrow, Bartow, Baldwin, Bibb, Bleckley, Butts, Carroll, Catoosa, Chattahoochee, Chattooga, Cherokee, Clarke, Clayton, Cobb, Coweta, Crawford, Crisp, Dade, DeKalb, Dooly, Dodge, Douglas, Emanuel, Fayette, Floyd, Fulton, Glascock, Gordon, Greene, Gwinnett, Hancock, Haralson, Harris, Heard, Henry, Houston, Jackson, Jasper, Jefferson, Johnson, Jones, Lamar, Laurens, Macon, Madison, Marion, Meriwether, Monroe, Montgomery, Morgan, Murray, Muscogee, Newton, North Fulton, Oconee, Oglethorpe, Paulding, Peach, Pike, Polk, Pulaski, Putnam, Rockdale, Schley, South Fulton, Spalding, Stewart, Sumter, Talbot, Taliaferro, Taylor, Telfair, Toombs, Treutlen, Troup, Twiggs, Upson, Walker, Walton, Warren, Washington, Webster, Wheeler, Whitfield, Wilcox, Wilkes, Wilkinson

Including the cities of:

Abbeville, Alamo, Americus, Athens, Atlanta, Barnesville, Bremen, Buena Vista, Butler, Calhoun, Cartersville, Carrollton, Cedartown, Chatsworth, Cochran, Columbus, Comer, Commerce, Conyers, Cordele, Covington, Crawford, Crawfordville, Dalton, Dallas, Decatur, Dublin, Douglasville, Eatonton, East Point, Eastman, Ellaville, Forsyth, Fort Moore, Fort Oglethorpe, Fort Valley, Franklin, Gray, Greensboro, Griffin, Hawkinsville, Hinesville, Homer, Jackson, Jeffersonville, LaFayette, Lawrenceville, Louisville, Lumpkin, Macon, Madison, Manchester, Marietta, Mcrae, Milledgeville, Monroe, Montezuma, Monticello, Mount Vernon, Newnan, Peachtree City, Pine Mountain, Preston, Riverdale, Roberts, Rome, Sandersville, Soperton, Sparta, Stockbridge, Summerville, Swainsboro, Talbotton, Thomaston, Toomsboro, Trenton, Vidalia, Vienna, Warner Robins, Warrenton, Washington, Watkinsville, West Point, Winder, Woodstock, Wrightsville, Zebulon

About the National Weather Service

The National Weather Service (NWS) is a part of the National Oceanic and Atmospheric Administration (NOAA).

The NWS describes its role as follows:

The National Weather Service (NWS) provides weather, water, and climate forecasts and warnings for the United States, its territories, adjacent waters and ocean areas, for the protection of life and property and the enhancement of the national economy. These services include Forecasts and Observations, Warnings, Impact-based Decision Support Services, and Education in an effort to build a Weather-Ready Nation. The ultimate goal is to have a society that is prepared for and responds to weather, water and climate events.

Read all the Cobb County Courier climate and weather coverage by following this link.