Unlike just a couple of decades ago, today extreme weather conditions are a standard occurrence – often multiple times a year. Heavy downpours, mighty winds, heat waves… These events are truly testing human resilience, our healthcare and water/electricity supply systems, and taking more lives with each passing year.

For instance, in Finland and Northern Europe, mortality is lowest when the warm-season months’ daily mean temperature is in the range of 12–17 °C, while in Mediterranean countries the same is true at 22–25 °C.That is where the question of heat waves and tropical nights comes into focus.

To capture the effects of global warming in coastal regions surrounding the Baltic Sea, a team of researchers from Klaipeda University carried out multiple studies that observed and analysed temperature changes during the hottest times of the year. Their observations demonstrated that extreme heat events in the South-eastern Baltic Sea coastal zone are strongly influenced by the thermal dynamics of adjacent water bodies.

Using long-term observations (1982–2024) in combination with Copernicus Climate Change Service data, the research team focused on changes in and around Klaipėda and Nida.

Their studies conclude that :

  • Extreme heat days (above 30°C) have become significantly more frequent.
  • Since 2018, at least one extreme heat wave and one tropical night have occurred every year.
  • The heatwave season is getting longer, now starting as early as May and extending into late August.
  • In Klaipėda, the average number of extremely hot days has more than doubled over recent decades.

Drawing on their findings, the team noted that understanding and forecasting heat waves and
tropical nights is vital not only for climate science but also for the development of sustainable
adaptation policies that protect ecosystems, human health, and coastal resilience. After all, the
notion of sustainability has long surpassed the boundaries of efficient resource use, expanding to include climate system stability, societal resilience, and the need for sustainable adaptation.

Although this study focuses on a certain area, its findings resonate broadly. The 10-km range around the Baltic Sea coastline is home to more than 15 million people, making this coastal zone one of the most densely populated and climate-sensitive areas in Northern Europe. During the warm season, these areas (especially urban centers and recreational beaches) welcome not only residents but also millions of tourists, so understanding the formation processes and dynamics behind extreme heat events is essential for developing climate resilient urban planning measures, protecting public health, and adopting sustainable cooling strategies in the region.