Moderate Expected Likely Heat Advisory Heat Advisory issued July 20 at 10:58PM CDT until July 21 at 8:00PM CDT by NWS Norman OK Jul 21, 12:00 PM → Jul 21, 8:00 PM WHAT: Dangerously hot conditions with air temperatures of 105 to108 degrees and heat index values up to 109 expected. WHERE: Portions of central, northwest, southern, southwest, andwestern Oklahoma and northern Texas. WHEN: From noon to 8 PM CDT Tuesday. IMPACTS: Hot temperatures and high humidity may cause heatillnesses. + Read More Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Updated: Jul 21, 1:28 AM Source: NWS Alert