Record June Sea Temperature Recorded Near Piran, Slovenia

Scientists at the Marine Biology Station Piran, part of Slovenia's National Institute of Biology, reported that the oceanographic buoy Vida, located 1.5 nautical miles north of the Piran lighthouse, measured a sea surface temperature of 29.9 °C in June 2024. This is the highest June temperature ever recorded at the buoy since its installation in 2004, more than four degrees above climatological expectations and surpassing the previous June record of 29.8 °C set in 2019.

The researchers noted that while a new absolute record for the buoy is possible during the ongoing heatwave, the long‑term trend of rising average sea temperatures is of greater concern. Repeated temperature spikes create prolonged thermal stress for marine organisms, leading to effects such as coral bleaching caused by the loss of symbiotic algae. The observation follows a strong Mediterranean-wide marine heatwave that affected the region last month.

Researcher Katja Klun and marine biologist Matjaž Ličer emphasized that the sustained multi‑decadal increase in average sea temperature, compounded by short‑term heat anomalies, threatens marine ecosystems across the Adriatic and broader Mediterranean Sea.