La ola de calor durará dos semanas.

The day began with temperatures already reaching into the high twenties, but by midday, the heat had intensified significantly across Slovenia. According to data from the Slovenian Environment Agency (ARSO), the hottest point was recorded in Nova Gorica around 12:40 PM, where the temperature reached 33 degrees Celsius. This marked the beginning of a prolonged period of extreme heat, which has been steadily increasing over the past few days. In areas such as Dolenje near Ajdovščina, Bilje near Nova Gorica, and Godnje within the municipality of Sežana, temperatures climbed to 32 degrees Celsius. Other locations, including Portorož, Kopře (Luka), Trbovlje, and Črnomlje, experienced temperatures of 31 degrees Celsius. Meanwhile, cities like Koper (Markovec), Hrastnik, Idrija, Kranj, Kubed, Maribor’s Airport, Litija, Mariča Vas, Ilirska Bistrica, Lendava, and Ljubljana on Vič were all reporting readings of 30 degrees Celsius.

As the weather continued its upward trajectory, concerns about the impact of this heatwave grew. The ARSO issued a yellow warning for the entire country, effective between noon and midnight, due to the rising thermal load. This warning is expected to escalate in severity as the days progress, particularly in the lowlands of the Primorska region and larger urban centers. Meteorologists predict that daily peak temperatures could reach up to 34 degrees Celsius, with some areas on the Primorska coast potentially exceeding 35 degrees Celsius by Sunday. They also anticipate that nighttime temperatures will rise to approximately 20 degrees Celsius, marking a significant shift in the typical summer climate.

This heatwave is part of a broader pattern of increasingly frequent and intense periods of extreme heat across Europe. According to Dr. Brane Gregorčič, a meteorologist at ARSO, the current wave of heat is expected to last until early July. He emphasized that while there may be minor fluctuations in temperature, substantial cooling is unlikely. The combination of strong solar radiation and the arrival of warm air masses from the south has created conditions favorable for prolonged periods of high temperatures. Gregorčič noted that mornings are becoming warmer than usual, with some regions experiencing what he described as "tropical" morning temperatures.

The phenomenon of heatwaves is not new, but their frequency and intensity have increased in recent years. Climate scientist Katja Kozjek Mihelec explained that a heatwave is defined as a period of continuous high temperatures lasting several days, which can pose risks to living organisms. She pointed out that Slovenia is divided into three climatic zones, each with specific thresholds for defining a heatwave. For central and eastern parts of the country, the threshold is set at 24 degrees Celsius, while the coastal Primorska region has a higher threshold of 25 degrees Celsius. Higher elevation areas, meanwhile, have a lower threshold of 22 degrees Celsius.

Historically, some of the most severe heatwaves occurred in 2003, 2013, 2022, and 2024. The 2013 heatwave was the strongest on record, with temperatures reaching 40.8 degrees Celsius at the airport in Cerklje ob Krki. The 2022 heatwave was notable for its widespread effects, including wildfires in the Karst region. Last year's June was particularly extreme, with temperatures averaging 3.6 degrees Celsius above normal and setting a new national record for sunny days. On June 26th, a temperature of 38.4 degrees Celsius was recorded in Dobliči near Črnomlje.

Looking ahead, projections suggest that temperatures could continue to rise, potentially increasing by two to three degrees Celsius by the end of the century. This would lead to more frequent and intense heatwaves, with longer periods of extremely hot days and nights. Kozjek Mihelec warned that such conditions could become commonplace, and even hotter summers might be possible. These changes are expected to increase the risk of heat-related illnesses and stress on both human populations and natural ecosystems.

Public health officials have also raised alarms about the dangers posed by these extreme conditions. Dr. Simona Perčič from the National Institute of Public Health (NIJZ) highlighted the need to protect vulnerable groups, such as the elderly, children, and individuals with chronic illnesses. She stressed that excessive heat can cause dehydration, skin rashes, heat exhaustion, and even heat stroke. She recommended that people stay cool, drink plenty of fluids, and avoid physical activity during the hottest hours of the day. Those who must work outdoors should take precautions, such as wearing light clothing and using sunscreen with a high protection factor.

In response to the ongoing heatwave, local authorities have taken steps to mitigate its effects. Emergency services have been deployed to assist with water supply issues caused by heavy rainfall in certain areas, such as Postojna and Gorenja Vas. Four volunteer fire departments have assisted in draining flooded buildings and protecting property. Regional emergency centers have documented 24 incidents related to the weather, highlighting the scale of the challenge faced by communities.

As the heat continues, experts warn that the situation could worsen, especially if no significant cooling occurs. While some relief may come from occasional rain showers, the overall trend suggests that the heatwave will persist for at least another week. With temperatures continuing to climb and the likelihood of further increases, the public is urged to remain vigilant and take necessary precautions to ensure safety and well-being during this extended period of extreme heat.