Dangerous heat wave to bake Iowa this weekend and next week: What you need to know

MASON CITY, IOWA — A significant heat wave is set to grip Iowa beginning this Sunday, with dangerously high heat index values expected to last through next week and potentially into the Fourth of July holiday weekend.

Meteorologists are warning that heat index values — the combination of air temperature and humidity that reflects what it actually feels like outside — could soar between 100° and 110° across much of the state, creating potentially life-threatening conditions for vulnerable residents.

When will the heat hit Iowa?

The hottest and most humid conditions are expected Sunday and Monday, with above-normal temperatures likely to persist well into next week. While forecasters note some uncertainty about exactly where the most extreme heat settles after Monday, the overall pattern points to a prolonged stretch of dangerous summer weather.

Iowa heat index forecast for Sunday

Here’s a look at projected heat index values across the state Sunday:

• Mason City: around 102°
• Algona: around 105°
• Des Moines: around 107°
• Ames: around 107°
• Cedar Rapids: around 106°
• Ottumwa: around 107°
• Council Bluffs: around 107°

How to stay safe during the Iowa heat wave

Health and weather officials urge Iowans to take the heat seriously and follow these precautions:

• Drink plenty of water throughout the day
• Take regular breaks in the shade or air conditioning
• Check on children, elderly neighbors and pets frequently
• Never leave anyone in a parked vehicle, even briefly
• Limit strenuous outdoor activity during peak afternoon heat

Residents should monitor local forecasts closely and have a plan for staying cool, particularly those without access to air conditioning at home.

Stay weather aware as this heat wave develops — conditions are expected to remain dangerous through much of the coming week.