What is a Heat Dome? What Can We Do to Deal With a Heat Dome?

Have you ever wondered, "What is a heat dome?” and why it makes headlines during extreme weather events? In fact, it is a high-pressure phenomenon that traps hot air over an area. 

This blog article will look at the heat dome meaning, how it occurs, its effects on the environment and health, and how to keep safe during one.

What is the definition of a heat dome?

What is a Heat Dome?

A heat dome is a meteorological phenomenon that causes warm air to rise to the surface and remain there for an extended period. 

The dome, similar to a pot lid, confines high-pressure air in one area. These enormous zones of hot air can cause destructive wildfires and drought conditions.

Furthermore, heat domes may prevent clouds from forming, leading to an abundance of sunshine and perhaps record-high temperatures.

What's a heat dome?

How is a heat dome different from a heat wave?

From the above definition, many people may ask, “What is a heat dome vs heat wave?” Although both are linked to extreme heat, there is a meteorological difference between them.

What is a heat wave? It is a period of unusually warm weather that lasts many days or even weeks. It is described in relation to a particular location's historical temperature averages. 

Moreover, a heat wave occurs when a particular location receives above-average temperatures over an extended time.

Heat waves vs heat domes 

In contrast, a heat dome is a distinct meteorological event.  As previously explained, a high-pressure system lingers over a certain area, trapping heated air. 

This can result in more severe and long-lasting heat than typical heat waves.

What Causes a Heat Dome?

Heat domes form as air temperature changes when it travels over land. It usually happens once the temperature of the tropical Pacific Ocean increases in the winter, forcing the air that flows over it to warm as well. 

Warmer air that moves over the ocean goes from west to east, becoming stuck on land and forming heat waves. 

What causes a heat dome to form?

Typically, the wind blows from west to east in a wavelike pattern, traveling north, then south, and then back north. The difference in air temperature accentuates the meandering, forcing the air to travel slowly or become stagnant. 

Finally, heat domes form as a result of these powerful, high-pressure atmospheric conditions.

Where Are Heat Domes an Issue?

Heat domes have been seen all throughout America and the world. In 1995, a heat wave struck the Midwest, killing around 600 people in the Chicago region. 

Furthermore, the North American heat wave of 1936 and the European heat wave of 2003 were both catastrophic examples of the "heat dome" phenomenon.

Another infamous incident was the 2011 Central U.S. heat dome, which burned most of Oklahoma, Texas, and Kansas. The heat and one of the worst droughts in US history decimated crops and dried up lakes and rivers.

A heat dome causes excessive temperatures

In late June 2021, a heat dome started over the West Coast states, setting new records for temperatures. 

Seattle exceeded 100 degrees for three days in a row, culminating at 108 on June 28. It was much hotter in Portland, where the temperature soared to 116 degrees, shattering the city’s previous record high of 107 degrees established in 1981.

How Does a Heat Dome Impact the US?

What is a heat dome, and how does it affect the US? When a heat dome settles over a region, the consequences can be extensive, severe, and even fatal.

Prolonged, intense heatwaves

During a heat dome, daytime temperatures may rise well above average, establishing new all-time highs. Meanwhile, nighttime temperatures remain exceptionally high, with little relief. 

In such instances, extended exposure to extreme heat can cause heatstroke, heat exhaustion, and higher death rates, especially among susceptible groups such as the very young and the elderly.  

A prolonged heatwave

Water stress and drought

Heat domes can roast the surface and even prevent moisture-laden weather systems from entering the region. Without replenishing rains, rivers diminish, soils dry out, and reservoir levels fall dangerously low. 

Consequently, farmers struggle with irrigation of crops, and cities may experience water restrictions or shortages.

Risk of wildfire

The fatal combination of bone-dry vegetation, severe heat, and a lack of rain greatly raises the risk of wildfire. When a fire starts under these conditions, it may spread quickly and become much more difficult to control.

Air quality problem

Heat dome affects air quality

The stagnant air beneath a heat dome concentrates pollutants near the ground, resulting in severe rises in air pollution levels. 

This can aggravate respiratory conditions such as asthma and cause public health alarms, particularly in places where pollution levels rise. 

How to Deal With the Heat Dome?

Heat domes are life-threatening to both people and animals. They may not only set record-high temperatures during the day, but also raise temperatures at night. 

As a result, it is critical to follow certain heat safety tips, as detailed below:

How to stay safe in extreme heat?

Closing Thoughts

Understanding what is a heat dome can help us better prepare for extreme heat events that are becoming more frequent due to climate change. By staying informed and taking proper precautions, individuals and communities can reduce the impact of prolonged heat waves and stay safe during these intense weather conditions.