Extreme Heat Warning

* WHAT...For the Dense Fog Advisory, visibility one quarter or less in dense fog. For the Heat Advisory, heat index values up to 105 expected. For the Extreme Heat Warning, dangerously hot conditions with heat index values up to 111 expected. For the Extreme Heat Watch, dangerously hot conditions with heat index values up to 106 possible.

* WHERE...Portions of western, central, north central and east central Iowa.

* WHEN...For the Dense Fog Advisory, until 10 AM CDT this morning. For the Heat Advisory, from noon today to noon CDT Sunday. For the Extreme Heat Warning, from noon to 9 PM CDT Sunday. For the Extreme Heat Watch, from Sunday evening through Monday evening.

* IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events. Hot temperatures and high humidity may cause heat illnesses. Low visibility could make driving conditions hazardous.