Extreme Heat Watch Issued for Mason City Area as Heat Index Could Hit 105 This Weekend

MASON CITY, Iowa — The National Weather Service issued an extreme heat watch for Mason City and much of North Iowa on Friday, warning that heat index values could climb to around 105 degrees Sunday and Monday as dangerous heat builds across the region.

A heat advisory takes effect Saturday, with heat indices expected to reach 99 degrees in Mason City that afternoon, according to the National Weather Service office in Des Moines. The advisory expands into an extreme heat watch for Sunday into Monday, when heat index values in Mason City are forecast to reach 98 degrees Sunday afternoon and 97 degrees Monday afternoon, the agency said.

Temperatures and humidity will continue building through the weekend and into early next week, forecasters said in a briefing issued at 4:40 a.m. Friday. Heat indices across the broader region are expected to run from 100 to 105 degrees Saturday, then approach 110 degrees or higher Sunday and Monday in some areas, according to the National Weather Service.

Forecasters also flagged the potential for thunderstorms, with a marginal risk of isolated severe weather for the Mason City area Saturday night. A greater slight risk of scattered severe storms is expected Sunday into early Monday, with damaging wind, hail and heavy rain cited as the main threats, according to the National Weather Service Storm Prediction Center.

The National Weather Service urged residents to take precautions as the heat builds. Recommendations include staying hydrated and taking breaks in air conditioning or shade, checking on elderly neighbors and those without air conditioning, and never leaving children or pets unattended in vehicles, the agency said.

Heat-related illness is possible under these conditions, and heat-related deaths are preventable, according to the National Weather Service. The agency said its next scheduled update on the forecast will come by 5 p.m. Friday.

Editor’s note: Confirm final heat index and severe weather risk figures against the National Weather Service’s afternoon update before publishing, since forecasts of this kind are frequently revised as the weekend approaches.