Key facts
- A significant heatwave is expected to affect the central and eastern United States, with temperatures potentially reaching the 100s.
- Over 100 record high temperatures and 250 record warm overnight lows are forecast through Saturday.
- Extreme heat warnings and watches are in effect for numerous cities across the U.S.
- Dangerous fire weather conditions are present in the Four Corners region, leading to critical wildfire risks.
- The UK is also bracing for a second heatwave, with temperatures forecast to reach the low to mid-30s Celsius.
- Heat health alerts have been issued across most of England, with amber alerts in effect for several regions.
A significant heatwave is set to grip large portions of the United States this week, with the National Weather Service warning of dangerous conditions and record-breaking temperatures. The heat dome is expected to build over the eastern two-thirds of the country, pushing temperatures into the 100s, exacerbated by high humidity. Major cities including New York City, Philadelphia, Baltimore, and Washington D.C. are anticipated to see record highs. Over 100 record highs and approximately 250 record-warm overnight lows are projected through Saturday night.
Extreme heat warnings are in effect for cities such as Nashville, St. Louis, Cincinnati, Kansas City, Des Moines, Chicago, and Detroit. Extreme heat watches cover much of the Northeast. Southern cities like Dallas, Little Rock, and Memphis will also experience dangerously high temperatures. The heat index, a measure combining temperature and humidity, could feel as hot as 115 degrees Fahrenheit in some central and eastern U.S. locations. This high heat is forecast to persist into next weekend across the Great Plains, Southeast, and Mid-Atlantic.
Meanwhile, the western U.S. faces dangerous fire weather conditions, particularly in the Four Corners area of Utah, Colorado, New Mexico, and Arizona. The National Fire Information Center described these conditions as 'extremely critical' for late June, with a high potential for new large fires. This comes after three firefighters died and two were injured in fast-moving wildfires near the Colorado-Utah border.
In the UK, heat health alerts have been implemented across most of England as the country prepares for its second summer heatwave. Amber alerts, indicating potential impacts on health services and the general population, cover regions including the East Midlands, South East, South West, East, and London. Yellow alerts apply to Yorkshire and the Humber, and the West Midlands, warning of effects on the elderly and vulnerable. Temperatures are expected to climb into the 30s Celsius over the weekend, potentially reaching a new high for the year on Monday, with forecasts suggesting 34-35C in London. This could make Monday the hottest start to Wimbledon on record. Northern and western areas of the UK are expected to be cloudier with showers, with cooler temperatures in places like Swansea and Glasgow. Parts of England have already experienced heatwave conditions, with temperatures exceeding 27C for three consecutive days. Scientists note that heatwaves are becoming more common and intense due to climate change, with June heatwaves above 28C being approximately 10 times more likely now than in the pre-industrial era.