Millions across the central and eastern US are under the summer’s first “heat dome” warning, with temperatures expected to reach or exceed 100F (37.7C) from this weekend through the end of next week. Affecting 170-200 million people from the Great Plains to mid-Atlantic states, including New York, New Jersey, Massachusetts, and Pennsylvania, the heatwave poses significant health risks, especially due to high overnight temperatures. Experts advise staying indoors, and some states are setting up cooling stations. Heat domes are becoming more common due to climate change, and extreme heat is the leading cause of weather-related fatalities in the US.
Millions of people across central and eastern US under ‘heat dome’ warning
United StatesClimate crisisEnvironmentNew YorkNew JerseyMassachusettsPennsylvaniaMaine
AI Summary
TL;DR: Key points with love ❤️Millions across the central and eastern US are under the summer’s first “heat dome” warning, with temperatures expected to reach or exceed 100F (37.7C) from this weekend through the end of next week. Affecting 170-200 million people from the Great Plains to mid-Atlantic states, including New York, New Jersey, Massachusetts, and Pennsylvania, the heatwave poses significant health risks, especially due to high overnight temperatures. Experts advise staying indoors, and some states are setting up cooling stations. Heat domes are becoming more common due to climate change, and extreme heat is the leading cause of weather-related fatalities in the US.
Trending- 1 June 20, 2025 (Friday): First day of summer; heatwave begins; temperatures start to rise across midwest; over 40 million people under heat alerts.
- 2 June 21, 2025 (Saturday): Extreme heat forecast to spread north and east into Minnesota, Wisconsin, Illinois, and Missouri.
- 3 June 22, 2025 (Sunday): States including Ohio, Pennsylvania, and New York begin to experience peak temperatures.
- 4 Early to midweek (June 23-25, 2025): The entire region stretching as far east as Maine will have high temperatures and humidity.
- 5 Next weekend (June 28-29, 2025): Respite expected as the 'lid' of strong high pressure eases.
- Risk of heat-related illnesses and heat stroke
- Increased mortality (extreme heat is leading cause of weather-related fatalities in US, 238 last year)
- Strain on the body without air conditioning, especially at night
- Need for cooling stations for vulnerable populations
- Policy changes regarding heat protections for outdoor workers (e.g., Florida banning such measures)
What: A 'heat dome' warning affecting scores of millions of people, bringing extreme temperatures (at or above 100F/37.7C) and high humidity. The phenomenon is linked to rising global temperatures and poses amplified risks of heat-related illnesses and fatalities. Some areas are setting up cooling stations, while others, like Florida, have removed heat protections for outdoor workers.
When: Beginning this weekend (June 21-22, 2025) and extending through the end of next week (around June 27-29, 2025). The heatwave coincides with Friday's (June 20, 2025) first day of summer. Temperatures began rising Friday lunchtime. Saturday will see heat spread north and east, Sunday will bring peak temperatures to some states, and by early to midweek, the entire region as far east as Maine will be affected. Respite is not expected until next weekend.
Where: Central and eastern US, specifically from the central Great Plains to mid-Atlantic states. States mentioned include New York, New Jersey, Massachusetts, Pennsylvania, Kansas, Nebraska, Iowa, Minnesota, Wisconsin, Illinois, Missouri, Ohio, and Maine. Phoenix, Arizona, and Florida are also mentioned in the context of heat policies.
Why: The 'heat dome' forms when high pressure from Earth’s atmosphere compresses warm air and pushes it down to the surface, trapping extreme hot air and humidity. This is becoming increasingly common due to rising global temperatures fueled by the climate emergency.
How: Forecasters are issuing warnings and advising residents to stay cool indoors. Some states and municipalities are setting up cooling stations to ease conditions for vulnerable populations. The National Weather Service tracks heat-related fatalities.