Adapting Adriatic Tourism to Climate Change: Challenges of Summer Heat and Opportunities for Seasonal Extension

The tourism-oriented Mediterranean Basin is increasingly exposed to intensified thermal stress under ongoing climate change, potentially affecting human health, outdoor activities, and tourism sustainability. Coastal tourism destinations along the eastern Adriatic are particularly vulnerable due to their climatic predisposition, which governs the duration of the tourist season and directly impacts the optimization of infrastructure and overall capacity utilization. This study assesses spatiotemporal changes in thermal risk across major tourism destinations along the eastern Adriatic coast using human biometeorological indicators derived from long-term meteorological observations. This study examines long-term thermal comfort conditions and trends in four highly visited eastern Adriatic destinations and evaluates their climatic suitability for both beach and sightseeing tourism.

Human thermal conditions were evaluated using the modified Physiologically Equivalent Temperature (mPET) index, allowing detailed assessment of heat stress intensity under Mediterranean conditions. Trends in the frequency, duration, and persistence of thermal stress categories were examined in the period 1996-2020 across all destinations.

Results show that over the last 25 years, monthly mean mPET values have increased in every month except May, while severe and extreme heat stress (mPET ≥ 35 °C) has become more frequent, especially in July and August. Although local geography and maritime influences create slight variations between cities, every location shows the same clear trend: summers consistently become uncomfortably hot. This thermal shift increases the touristic attractiveness of the shoulder seasons when comfortable conditions are more frequent. While summer still offers the most favorable climatic conditions for beach tourism, the frequency of beach-comfortable conditions has declined this season. Conversely, thermal conditions for sightseeing have become more favorable in April and November, while deteriorating significantly in September. Surprisingly, a downward trend in May's mPET values indicates that this month is becoming less suitable for the beach but increasingly favorable for sightseeing.

The outcomes suggest increasing vulnerability of East Adriatic coastal tourism systems to climate change, particularly regarding human exposure to prolonged daytime heat stress during the peak tourist season. Our analysis also indicates that, despite the risks of climate change, the tourism sector has a unique 'window of opportunity' to extend the beach season from spring into autumn. Since the shoulder seasons are becoming more comfortable for sightseeing, there is a real chance to adapt by combining the region’s rich cultural heritage with these better weather windows—especially as modern tourists look for more than just a traditional beach holiday.