…HEAT ADVISORY REMAINS IN EFFECT UNTIL 8 PM CDT THIS EVENING… …HEAT ADVISORY IN EFFECT FROM 1 PM TO 9 PM CDT SATURDAY… The National Weather Service in Sioux Falls has issued a Heat Advisory, which is in effect from 1 PM to 9 PM CDT Saturday. * HEAT INDEX VALUES…Today will be 100 to 105 degrees while on Saturday they will climb to 105 to 110 degrees.