Heat Advisory issued September 18 at 2:58AM CDT until September 18 at 8:00PM CDT by NWS St Louis MO
Issue date: 2026-09-18T07:58+00:00
* WHAT...Heat index values up to 105. * WHERE...In Illinois, Fayette IL, Montgomery IL, Calhoun IL, Greene IL, Jersey IL, and Macoupin IL Counties. In Missouri, Boone MO, Callaway MO, Lincoln MO, and Montgomery MO Counties. * WHEN...Until 8 PM CDT this evening. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses.
