heat dome

A month into summer 2024, the vast majority of the U.S. population had already experienced at least one extreme heat wave, and millions of people were under heat alerts, with forecasts warning of more ahead. Death Valley hit 125 degrees Fahrenheit (51.7 Celsius) or higher for nine consecutive days in early July. Las Vegas broke its all-time heat record at 120 F (48.9 C). Days of 100-degree heat dried out the California landscapes, fueling wildfires there and in the Northwest. Oregon reported several suspected heat deaths. Globally, the planet had its hottest day in at least eight decades of recordkeeping on July 21 – and then broke the record again on July 22, according to the European Union’s Copernicus Climate Change Service. The extreme heat is part of a longer trend: Each of the past 13 months has been the hottest on record for that month globally, including the hottest June, the EU service reported in early July. It also found that the average temperature for t...

The heat wave that left more than 100 million people sweating across the eastern U.S. in June 2024 hit so fast and was so extreme that forecasters warned a flash drought could follow across wide parts of the region. Prolonged high temperatures can quickly dry soils, triggering a rapid onset drought that can affect agriculture, water resources and energy supplies. Many regions under the June heat dome quickly developed abnormally dry conditions. The National Oceanic and Atmospheric Administration’s hazard outlook map shows flash drought warnings in yellow and areas forecast to have a high risk of excessive heat in early July in red. NOAA Climate Prediction Center The human impacts of the heat wave have also been widespread. In Ohio and Pennsylvania, emergency room visits for heat-related illnesses surged. Several Massachusetts schools without air conditioning closed to protect kids and teachers...

Tropical Storm Hilary made landfall on Mexico’s Baja peninsula, and its damaging wind and heavy rainfall moved into Southern California on Aug. 20, 2023. For the first time ever, the National Hurricane Center had issued a tropical storm watch for large parts of Southern California. Forecasters warned of a “potentially historic amount of rainfall,” and the governors of California and Nevada declared states of emergency. Hurricane scientist Nick Grondin explained ahead of landfall why the storm, with help from El Niño and a heat dome over much of the country, could bring flash flooding, wind damage and mudslides to the region. How rare are tropical storms in the Southwest? California had only one confirmed tropical storm landfall in the past. It was in September 1939 and called the Long Beach Tropical Storm. It caused about US$2 million dollars in damage in the Los Angeles area – that would be about $44 million today. A hurricane in 1858 came close bu...

The heat dome that descended upon the Pacific Northwest in late June 2021 met a population radically unprepared for it. Almost two-thirds of households earning US$50,000 or less and 70% of rented houses in Washington’s King, Pierce and Snohomish counties had no air conditioning. In Spokane, nearly one-quarter of survey respondents didn’t have in-home air conditioning, and among those who did, 1 in 5 faced significant, often financial, barriers to using it. Imagine having no way to cool your home as temperatures spiked to 108 degrees Fahrenheit (43 Celsius), and 120 F (49 C) in some places. People in urban heat islands – areas with few trees and lots of asphalt and concrete that can absorb and radiate heat – saw temperatures as much as 14 F (7.8 C) higher than that. Extreme heat disasters like this are becoming increasingly common in regions where high heat used to be rare. Blackouts during severe heat waves can also leave residents who believe they are...