x
Breaking News
More () »

What is a heat dome and when is it expected to hit Ohio?

Ohio is just one of several states under a Heat Advisory.

OHIO, USA — Extreme heat alerts are in effect for tens of millions of people in the United States as cities across the country break heat records.

States in the Midwest started experiencing hot temperatures on Monday in a dangerous heat wave. It's expected to stretch from Iowa to Maine in the Northeast and last until at least Friday.

Ohio is just one of several states under a Heat Advisory. Heat indices will rise between 100 and 106 degrees in the Buckeye state with the possibility of it feeling hotter.

High humidity will also make it feel exceptionally uncomfortable to be outside and elevate the risk of heat-related illnesses.

RELATED: Heat Advisory in effect for central Ohio; heat indices could reach 105+ degrees this week

What’s causing temperatures to be so hot are heat domes.

What is a heat dome? 

A heat dome is when a large ridge of high pressure creates sinking air in the atmosphere. It’s like putting a lid on the atmosphere that prevents the heat from the ground from mixing with the cooler air. 

The sinking air makes it hotter and can reduce air quality levels.

What’s the difference between a heat wave and a heat dome?

A heat wave is a period of abnormally hot weather generally lasting more than two days. They can happen with or without high humidity.

Heat waves have the potential to cover a large area, exposing a high number of people to hazardous heat.

The longest heat wave recorded in Columbus is tied for 12 days (at or above 90). This happened in 1949, 1999 and 2020. It looks like we could potentially rival that all-time record as our temps will remain above 90 through the week.

Is Ohio under a heat dome?

Not quite yet.

The heat dome is currently in the Northeast region of the country as they’re seeing highs in the 90s. It will then shift west later in the week impacting more of the Midwest, including Ohio.

The good news is that there will be a brief dip in humidity on Wednesday, providing the state with a small bit of relief.

The bad news is that the heat will be highest on Friday and Saturday when the heat dome shifts west toward Ohio. Temperatures will be in the mid to upper 90s and it could feel as hot as 106.

How to stay safe and cool in hot weather 

  • Drink plenty of water. Do not wait until you are thirsty.
  • Stay in air conditioning whenever possible. If you do not have an air conditioner, use movie theaters, malls, libraries and other public places that are cool.
  • Avoid beverages with alcohol, caffeine and sugar because they will dehydrate you.
  • Eat light meals.
  • Wear lightweight, light-colored clothing.
  • Avoid strenuous activities and limit them to morning and evening hours.
  • Learn the signs and symptoms of heat-related illnesses and how to treat them.
  • Check on family members, friends and neighbors.
  • Never leave people or pets in a closed car.

Before You Leave, Check This Out