Weather in Alghero

The chart averages one year of daily readings from each of twelve cities around the basin, built from the same ERA5 record as the table higher up this page. Since 1950 the index has risen about 0.17 °C a decade; since 1996, about 0.36 °C — roughly twice as fast. The ten warmest years of the seventy-six all fall inside the last twelve, and 1992 was the last one to come in below the 1961–1990 average.

That is not a local quirk. MedECC, the region's own assessment body, puts the Mediterranean about 20% ahead of the global warming rate, with annual temperatures already around 1.4 °C above 1880–1899. It is one of the areas the scientific literature has long called a climate change hotspot.

The water followed the air. Copernicus recorded 2024 as the warmest year yet for Mediterranean sea surface temperature at 21.50 °C, and 2025 as the second at 21.35 °C — about 1 °C above the 1991–2020 average, with the surface warming at roughly 0.4 °C a decade. In each of the last three years the whole basin has passed at least “strong” marine heatwave conditions, and at least half of it “severe” or “extreme”.

The cost shows up in the things that hold a coast together. Posidonia oceanica, the seagrass meadow that traps sediment and keeps sand on beaches like these, covers around 19,000 km² along European coasts and has lost up to a third of it in fifty years. Sea level in the basin rose about 0.7 mm a year between 1945 and 2000; over the last two decades it has run closer to 3 cm a decade.

On Sardinia the shortage arrives as water rather than heat. After the dry year to July 2024 the island's reservoirs fell far enough for a state of emergency, and World Weather Attribution found that human-caused warming had made a drought of that severity about 50% more likely. The striking part is what did not change: rainfall. The shift was in temperature and evaporation — the same rain, leaving faster.