Heat Dome to Bring Extreme Temperatures and Health Risks Across U.S.

A significant heat dome is set to envelop large portions of the United States, bringing extreme temperatures and heightened health risks to millions. Beginning June 19, 2025, this meteorological phenomenon will impact major cities including Chicago, Denver, and Pittsburgh, with temperatures expected to soar into the high 90s°F (30s°C) and some areas potentially reaching or exceeding 100°F (38°C).

A heat dome occurs when a high-pressure system traps hot air over a region, leading to prolonged periods of extreme heat and humidity. This stationary atmospheric condition prevents convection and precipitation, effectively "capping" the hot air below. Factors contributing to heat domes include sea surface temperature anomalies and the influence of La Niña.

Forecasted Temperatures:

• Chicago, IL:
• Thursday, June 19: Partly sunny, high of 81°F (27°C).
• Friday, June 20: Partly sunny and warm, high of 85°F (30°C).
• Saturday, June 21: Windy and hot, high of 94°F (34°C).
• Sunday, June 22: Partly sunny, windy, and very hot, high of 96°F (36°C).

• Monday, June 23: Sizzling sunshine, breezy, and very hot, high of 96°F (36°C).

• Denver, CO:

• Thursday, June 19: Sunny, high of 95°F (35°C).
• Friday, June 20: Sunny to partly cloudy, breezy, and hot, high of 101°F (38°C).
• Saturday, June 21: Blazing sunshine and hot, high of 101°F (38°C).
• Sunday, June 22: Very warm with sunshine, high of 97°F (36°C).

• Monday, June 23: Intervals of clouds and sun, high of 75°F (24°C).

• Pittsburgh, PA:

• Thursday, June 19: Some sun with a couple of showers and a heavy thunderstorm, high of 82°F (28°C).
• Friday, June 20: Partly sunny and less humid, high of 85°F (30°C).
• Saturday, June 21: Hot and more humid with sun and some clouds, high of 91°F (33°C).
• Sunday, June 22: Mostly sunny, very hot and humid, high of 98°F (36°C).
• Monday, June 23: Very hot and humid with sunshine, high of 98°F (37°C).

The National Weather Service has issued heat advisories, warning of potential health hazards, especially for those without adequate cooling or hydration. Residents are advised to stay hydrated, avoid prolonged outdoor activities, and utilize air-conditioned environments when possible.

Extreme heat poses significant health risks, particularly to vulnerable populations such as the elderly, children, pregnant women, and individuals with chronic health conditions. Heat-related illnesses range from heat exhaustion to heat stroke, which can be fatal if not promptly addressed.

Preventive Measures:

• Stay Cool: Remain in air-conditioned environments as much as possible. If air conditioning is unavailable, seek out public spaces like shopping malls or libraries.
• Stay Hydrated: Drink plenty of fluids, avoiding beverages that contain alcohol, caffeine, or excessive sugar.
• Dress Appropriately: Wear lightweight, loose-fitting, light-colored clothing made from breathable fabrics to promote airflow and aid in sweat evaporation.
• Limit Outdoor Activities: Avoid strenuous activities during peak heat hours, typically between 10 a.m. and 4 p.m.
• Check on Vulnerable Individuals: Regularly monitor those at higher risk, including older adults, young children, and individuals with pre-existing health conditions.

The impending heat dome is expected to have wide-ranging economic and social effects. Increased use of air conditioning will likely lead to higher electricity consumption, potentially straining power grids and leading to increased utility bills. Outdoor events, including Juneteenth celebrations and the 33rd annual Giant BBQ Battle in Washington, D.C., may be affected, with organizers and attendees needing to take precautions against the extreme heat. High temperatures can adversely affect crops, particularly in the Midwest, where corn and soybean yields may suffer due to heat stress.

Heat domes have been linked to severe heat waves in the past, such as the 2021 North American Heat Dome, which resulted in significant mortality and environmental damage. Research indicates that climate change is increasing the frequency and intensity of such events. Assistant Professor Mostafijur Rahman from Tulane University emphasizes that "extreme heat is a health crisis that will only worsen due to the threat of climate change."

As the heat dome intensifies, residents are urged to take necessary precautions to protect themselves and their communities. Staying informed through local weather updates and adhering to public health advisories will be crucial in mitigating the risks associated with this extreme weather event.