North Iowa Faces Extreme Heat Warning, Severe Storm Threat Through Monday

MASON CITY, Iowa — Dangerous heat and the threat of severe thunderstorms will grip north Iowa into next week, the National Weather Service said in an update issued Saturday afternoon.

A heat advisory is in effect for the Mason City area through noon Sunday, with an extreme heat warning taking over Sunday afternoon as heat indices climb toward 110 degrees or higher, according to the weather service’s Des Moines office. The advisory was issued at 5:02 p.m. Saturday.

Heat index values in Mason City are forecast to reach 113 degrees Sunday afternoon before easing to 103 degrees Monday afternoon, according to weather service forecast data. Farther south, an extreme heat watch remains in effect across central Iowa for Monday.

Meanwhile, severe thunderstorms are possible after midnight tonight, mainly across northern Iowa, forecasters said. Damaging wind gusts are the primary hazard, with hail and an isolated tornado also possible. Storms are expected to track east-southeast at about 35 mph, weakening gradually as they move through the region.

The weather service placed north Iowa, including Mason City, in a slight risk — a 2 on a 5-point scale — for severe weather overnight into Sunday morning.

A second round of storms could develop Sunday evening into early Monday, forecasters said, though timing and coverage remain uncertain. That threat also places north Iowa under a slight-risk designation, with damaging wind again the main concern. Forecasters said to stay up to date with the latest forecast as details become clearer.

Officials urged residents to guard against both hazards — staying weather-aware amid the storm threat, and taking breaks in air conditioning or shade, drinking plenty of water, and never leaving children or pets unattended in vehicles as heat indices soar.

Heat exhaustion symptoms include dizziness, thirst, heavy sweating, nausea and weakness, and can be treated by moving to a cooler area, loosening clothing and sipping cool water, according to the weather service. Heat stroke — marked by confusion, dizziness and unconsciousness — is a medical emergency requiring an immediate call to 911, since it can cause death or permanent disability without prompt treatment.