US, Mexico brace for record heatwave; South Africa hit by deadly floods
Alice Nightingale-Smith
A powerful high-pressure system is driving temperatures 10–15°C above seasonal averages across the western U.S. and Mexico, with extreme heat warnings in California and Arizona. At the same time, South Africa’s Western and Northern Cape provinces are battered by heavy rain and strong winds, raising fears of flash floods and landslides. The weather follows a deadly flooding event earlier this month that killed one person and displaced thousands.
This week, a high-pressure system is pushing temperatures across the western United States and Mexico well above seasonal norms, with daytime highs forecast to be 10–15°C (18–27°F) higher than average in some areas. The U.S. National Weather Service has issued heat advisories for parts of California and Arizona, including an extreme heat warning for Monday and Tuesday in places like Palm Springs, where temperatures could reach 40–43°C (104–110°F). Temperatures are expected to climb into the upper 30s °C before shifting eastward toward the Midwest by the weekend.
Meanwhile, extreme weather persists in South Africa, with heavy rain and strong winds heightening the risk of flash floods. Since early Sunday, moisture from the Atlantic Ocean has been drenching the Western and Northern Cape provinces, continuing through the weekend. From Monday to Wednesday, rainfall could exceed 200 mm in parts of the Western Cape, with some mountainous areas receiving nearly 300 mm. The South African Weather Service has issued multiple warnings, emphasizing the threat of flash floods, landslides, rockslides, and damage to infrastructure and property.
Heavy rain is expected to combine with strong winds, posing danger across large parts of southern South Africa, including the Western and Eastern Cape. Northwest to westerly winds could reach speeds above 97 km/h (60 mph) early in the week, especially over hilly and mountainous terrain such as the Cape Fold Mountains.
This latest alert follows a heavy downpour that caused flooding, road closures, and infrastructure damage in the Western and Eastern Cape from May 5–7. During that event, over 300 mm of rain fell in some areas, prompting evacuations in the Gamtoos Valley after the Kouga Dam exceeded capacity. Power outages and at least 45 road closures stranded many communities. One person died in Knysna, Western Cape, while over 2,000 residents were forced to relocate to emergency shelters.