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Geneva
Friday, May 24, 2024

2023: Summer of extremes

The summer of extreme temperatures continues. After the hottest July on record, high-impact weather conditions continue into August. Moderate and severe heat alerts for the next few days have been issued by several national meteorological and hydrological services in Europe, including France, Switzerland, Germany, Poland, Croatia, Italy, Greece, Hungary, Austria and Lithuania.

July out of the ordinary

According to data from the Copernicus Service, the European Union's earth observation program, July was the hottest month on record. These temperatures were associated with heat waves in large parts of North America, Asia and Europe. Forest fires, such as those in Canada and Greece, had a major impact on people's health, the environment and economies.

High temperatures ahead

Over the weekend, maximum temperatures could reach 40°C in some regions of southern France, according to Météo-France. This situation is due to a strong anticyclone and warm subtropical air from North Africa. Météo-Suisse has issued level 3 orange alerts for most of the country (from Saturday in the case of Geneva), with maximum daytime temperatures between 33 and 35 degrees and high night-time temperatures. According to Alvaro Silva, climatology expert at the World Meteorological Organization (WMO), "this is normal and comes as no surprise". He added that "the frequency and intensity of many extreme events, such as heat waves and heavy precipitation, have increased over recent decades. It's a safe bet that human-induced climate change due to greenhouse gas emissions is the main driver".

Fires

Spain, including the Canary Islands, and Portugal were clearly experiencing extreme heat. On August 17, the Tenerife fire remained out of control, with more than 2,600 hectares burnt and people evacuated. Dry conditions, maximum temperatures in excess of 30°C, night-time temperatures above 20°C and wind gusts in excess of 50 km/h were observed on August 16 and 17 by weather stations in Tenerife.

Other regions affected

Some parts of the Middle East are expected to experience temperatures in excess of 50°C. Japan also experienced a prolonged heat wave, with many records broken.

North America

Canada's record forest fire season continues. As of August 17, more than 600 fires were out of control across the country. Heat alerts in western Canada and warnings, or findings, of poor air quality due to smoke were issued in several regions.

In the United States, the National Weather Service reports that intense heat has settled over the Plains and will extend over much of central and southeastern parts of the country until early next week. Temperatures in excess of 38°C are expected in many areas, and numerous records are likely to be broken.

Hurricane Hilary

Hurricane Hilary, which was moving off the coast of Mexico, has intensified to become a major Category 4 phenomenon, according to the US National Hurricane Center, the specialized weather center of the WMO. Heavy rainfall associated with Hilary is expected to hit California from Sunday evening local time. It will be the first tropical storm to hit this region since 1939. Rainfall of 5 to 10 centimeters will be possible over parts of southern California and Nevada. Three tropical systems are currently evolving in the Pacific: Greg, Fernanda and Cyclone Hilary.