SIOUX FALLS, S.D. (KELO) — A heat advisory is in effect on Saturday from 1:00 p.m. to 9:00 p.m. (CDT).

The heat index may reach 109 degrees in south central and southeast South Dakota. Hot temperatures and high humidity could cause excessive heat illnesses.

As precautions, drink plenty of fluids, stay in the air-conditioning if possible and stay out of the sun. Young children and pets should never be left unattended in vehicles even for a few minutes. If pets are outside, assure they have shade and plenty of water.