Extreme Heat Warning in Effect Through Wednesday for Mason City and North Iowa — Severe Storms Also Possible Tonight

Mason City, Iowa — North Iowa is in the grip of a dangerous heat wave, and forecasters say there’s no relief in sight through the Fourth of July holiday weekend. The National Weather Service in Des Moines has issued an Extreme Heat Warning through Wednesday evening for the eastern two-thirds of Iowa, including Mason City and the surrounding region.

Heat Index Values Will Exceed 100°F for Days

Temperatures in the 90s combined with high humidity will push heat index values well above 100°F across North Iowa for multiple consecutive days. According to the NWS forecast, Mason City can expect heat index values of around 100°F on Monday, dropping slightly through the week but remaining dangerously high through the holiday weekend.

Overnight temperatures offer little escape, with lows staying in the upper 70s and 80s — making it difficult for the body to recover from the daytime heat.

Severe Storms Possible Tonight in Northwest Iowa

On top of the heat threat, the National Weather Service has issued a Slight Risk (Level 2 of 5) for severe storms tonight, primarily in northwestern Iowa, from 9 p.m. tonight through 6 a.m. Tuesday. The primary threats include:

• Damaging winds of 60 to 70 mph
• Large hail up to 1.5 inches in diameter
• Isolated tornadoes (a tornado or two possible)

Mason City sits on the edge of the storm risk area. Residents are urged to stay weather aware, have multiple ways to receive warnings, and know their nearest indoor shelter location.

How to Stay Safe in the Heat

The NWS is urging everyone in the region to take the heat seriously. Here’s what forecasters recommend:

• Drink plenty of water — even if you don’t feel thirsty
• Spend time in air conditioning during the hottest parts of the day
• Avoid strenuous outdoor activity during peak afternoon heat
• Wear lightweight, light-colored, loose clothing
• Never leave children or pets unattended in vehicles — even briefly
• Bring pets indoors or provide shade and plenty of fresh water
• Check in on elderly or ill neighbors and family members
• Avoid alcohol and caffeine, which can accelerate dehydration
• Watch for signs of heat exhaustion and heat stroke