Over the past ten years, Belgrade has recorded an average of 41.9 tropical nights per year. That amounts to just under half of all summer nights. Why is this happening, and what can be changed?
Both urbanisation and climate change are to blame for Belgrade’s warming, writes Dr Ivan Simić of the Faculty of Architecture in Belgrade. In an article for Klima 101, he explains how this trend can be halted and even reversed.
This year’s State of the European Climate report brought a wealth of interesting data on various climate impacts, measured through different climate indicators. One such indicator is thermal stress, which can be expressed through the number of tropical nights – nights during which the air temperature does not fall below 20°C. Such conditions make sleep and rest more difficult, reduce daily comfort, and can even affect health.
According to the report, most of Europe recorded a near-average number of tropical nights during 2025. Southern Europe, however, stood out as a clear exception, reports Klima 101.
Parts of southern Europe, particularly the Iberian Peninsula and coastal areas around the Mediterranean Sea, experienced up to 30 more tropical nights than average, while some localised areas recorded as many as 40 additional tropical nights. The Balkan Peninsula did not deviate to quite the same extent, but it nevertheless contains some noteworthy anomalies. Unfortunately, one of them is the region of the southern Pannonian Basin, which includes Vojvodina.
Rising thermal stress in Vojvodina
The growing thermal stress in Vojvodina is among the clearest signs of climate change in south-eastern Europe. Several mutually reinforcing geographical and climatic factors are causing the region to warm more rapidly and experience more intense heat stress than most other parts of the Balkans.
Belgrade – tropical nights as the new normal
At the southern edge of this increasingly hot area lies Belgrade, the largest urban agglomeration in the southern part of the Pannonian Basin. Belgrade is therefore already situated within a region experiencing above-average temperature increases driven by climate change.
According to the tropical nights indicator, Belgrade was at least 10 tropical nights hotter in 2025 than the rest of an already overheated region. The State of the European Climate report shows that the number of tropical nights increased in this area during 2025. However, 2025 was not an isolated extreme event – it represents the new normal for Belgrade.
Over the past decade, Belgrade has averaged 41.9 tropical nights annually, which is just under half of all summer nights. For comparison, the average between 1961 and 1990 was only 7.3 tropical nights per year. The last time Belgrade experienced such a low – and once typical – number of tropical nights was as far back as 1997.
Although dedicated scientific research would be needed to confirm the exact causes of such a dramatic change, one likely suspect stands out: the urban heat island effect, which has reached significant proportions in Belgrade. This phenomenon amplifies the temperature stress already caused by climate change. In fact, urbanisation and climate change work hand in hand when it comes to the increase in tropical nights.
Combating heat through smarter urban planning
Given that urbanisation is widely regarded as an inevitable process, a natural question arises: what model of urban development causes the least increase in temperature and thermal stress?
This is an extremely complex question to which science has yet to provide a complete and unequivocal answer. There are many differing viewpoints, depending on the scale being considered (country, region, or city) and whether the focus is on climate change mitigation or adaptation. The reality is that every city is unique, shaped by its own history and key factors, including its morphology, climate, hydrology, politics, economy, and energy systems. Consequently, solutions must vary from one city to another, and the most climate-friendly urban development model will differ accordingly.
For example, a densely built city centre intensifies the urban heat island effect in Belgrade. Yet a similar urban form – narrow streets, compact construction, and reflective white materials – in Marrakesh, Morocco, provides shade for much of the day and is therefore considered an appropriate solution there.
Belgrade’s temperate continental climate supports the growth of large-canopy urban trees, meaning that the way shade is created differs significantly from places such as Morocco or the Middle East. Nevertheless, one scientifically and practically established principle is already clear: the characteristics of land cover and land use largely determine whether thermal stress is intensified or reduced.
These characteristics are combined in the composite parameter known as Land Use–Land Cover (LULC). Thanks to satellite-based Earth observation programmes such as Europe’s Sentinel system and the United States’ Landsat programme, researchers now possess detailed data on land surface temperatures and land use patterns. These data reveal that some forms of urban development contribute far more to thermal stress than others.
Among the least desirable patterns are industrial and brownfield areas, dense transport corridors and traffic interchanges, and closely packed residential and commercial developments lacking adequate greenery. By contrast, green infrastructure, especially large-scale elements such as forest parks and wetlands, ranks among the most effective cooling features.
Belgrade – An urban planning remedy for an urban planning problem
An analysis of Belgrade’s urban heat island map has shown that large green spaces such as Košutnjak, Zvezdara Forest, Ušće Park, and the city’s green riverbanks have the most beneficial cooling effect and represent the only adequate planning response under conditions of intensive urbanisation. Residential neighbourhoods located near such green areas experience, on average, 10 to 20 fewer tropical nights per year, while green corridors along riverbanks allow cooler air above the rivers to penetrate built-up districts.
Natural land cover should not remain confined to parks, forests, and wetlands. It should become an integral part of residential urban blocks as well.
Planning regulations in countries such as Switzerland, the United Kingdom, and the Netherlands have already introduced restrictions on underground excavation and the covering of natural ground surfaces for parking facilities and other residential infrastructure. Before any development begins, biodiversity, geological conditions, and hydrological characteristics are assessed so that they can be incorporated into the planning process. The final design should respect the existing natural environment and, where possible, improve it for the benefit of residents as well as local flora and fauna.
Only through such approaches can the urban heat island effect be reduced and the number of unbearably hot nights in Belgrade be brought down. Since urban warming results from both urbanisation and climate change, the problem will continue to worsen in the future – even if all further heat-promoting construction were halted tomorrow.
In other words, we must not merely stop this trend; we must reverse it if we want Belgrade to remain even remotely comfortable and pleasant to live in, concludes Ivan Simić in his article for Klima 101.
(Vreme, 11.06.2026)
https://vreme.com/mozaik/beograd-tropsko-leto-tropske-noci-klimatske-promene-temperature/