Why do we see so many powerful storms this year?

A heatwave is currently affecting Slovenia, with temperatures expected to remain high until early July. According to meteorologist Brane Gregorčič from the Agency for Environment of the Republic of Slovenia (ARSO), this heatwave will persist without significant cooling periods. The situation has already begun to impact parts of Europe, particularly regions such as the Iberian Peninsula, France, Switzerland, and northern Italy, where temperatures could deviate by up to 10 degrees Celsius above normal levels. In Slovenia, the initial effects of the heatwave are most pronounced in western areas, but they are expected to spread further across the country during the coming week.

The current weather conditions indicate that today is the coolest day in central and southwestern Slovenia, although temperatures are still expected to exceed 30 degrees Celsius in many areas. From now on, temperatures between 30 and 35 degrees Celsius can be anticipated until the beginning of July. Gregorčič noted that while there might be minor fluctuations, no substantial cooling is expected. He also mentioned that morning temperatures will approach tropical levels, especially starting from Sunday. This is due to the shortest nights and strongest sunlight in June, which combine with the inflow of hot air to increase thermal stress significantly.

The Environmental Agency has issued a yellow alert level warning, which may be upgraded if the heat persists longer than initially predicted. The hottest conditions are expected in the Goriška region, the Vipava Valley, and Slovenian Istria, where temperatures could surpass 35 degrees Celsius.

Heatwaves are defined as prolonged periods of high temperatures that can pose risks to living organisms. Climatologist Katja Kozjek Mihelec explained that the number of heatwaves has increased in recent years. In Slovenia, a heatwave occurs when the average daily temperature exceeds specific thresholds over three consecutive days. These thresholds vary depending on the climatic zone: 24°C for central and eastern lowlands, 25°C for the coastal area, and 22°C for higher elevations.

The arrival of hot air can result from either maritime or continental subtropical air masses. Maritime air masses bring more humidity and less distinct temperature trends, leading to more humid and oppressive heatwaves. Continental subtropical air masses are drier and hotter, creating more stable conditions with greater temperature variation throughout the day. While these conditions lead to higher daytime temperatures, they also allow for some cooling at night, making them suitable for longer but slightly less intense heatwaves.

In recent decades, both the duration and intensity of heatwaves have been increasing. Notable heatwaves occurred in 2003, 2013, 2022, and 2024. The 2013 heatwave was the most severe recorded in Slovenia, reaching a record temperature of 40.8°C at Cerklje ob Krki airport on August 8. The 2022 heatwave was long-lasting and had significant regional impacts, including extensive wildfires in the Kras area along the coast. June last year was the most extreme summer month according to ARSA measurements, being 3.6°C above average and marked by unprecedented sunshine. A record-breaking temperature of 38.4°C was recorded in Dobliči near Črnomlje on June 26.

Looking ahead, climate projections suggest that temperatures could rise by an additional 2 to 3 degrees Celsius by the end of the century. This would likely result in more tropical nights and more days exceeding 30°C. Heat stress is expected to intensify, potentially leading to more heat-related health issues. Kozjek Mihelec warned that heatwaves similar to the one experienced in 2013 could become more common, with even hotter summers possible in the future.

Health professionals emphasize the importance of protecting vulnerable populations during heatwaves. Dr. Simona Perčič from the National Institute of Public Health (NIJZ) highlighted that older adults, children, patients, and individuals with poorer living conditions are at higher risk. She recommended avoiding excessive exposure to the sun, staying hydrated, and seeking shade during peak hours. Public health advisories include moving activities to cooler times of the day, wearing appropriate clothing made from natural fabrics, and using sunscreen with a protection factor of at least 30. It is crucial to monitor weather warnings and adjust activities accordingly to prevent heat-related illnesses such as heat exhaustion and heatstroke, which require immediate medical attention.