Late September with abnormal heat, peaks up to 30 degrees in Central-Northern Italy.

The last weekend of September is set to bring an unusual heatwave and late-summer conditions across much of Italy. High pressure, reinforced by warm currents of African subtropical origin, will ensure stable and predominantly sunny weather from North to South, with only isolated showers possible in the far South and Sicily.

Temperatures will see a general rise, particularly noticeable in the Central-North and Sardinia, where they could reach or approach 30 degrees Celsius, with thermal anomalies of up to 6-7 degrees above the seasonal average. Along the Tyrrhenian regions and the Major Islands, locally even higher values are expected. This phase of unusual heat is likely to persist at least until Wednesday, September 30th.

The unseasonal heatwave affecting Italy in the second half of September 2026 is caused by a particular atmospheric configuration. This involves a "mixed" anticyclone, of Azorean origin (from the Atlantic Ocean) but supplemented by contributions of hot air coming directly from the Sahara Desert in North Africa. This phenomenon represents an anomalous meteorological situation for the period.

This dynamic is considered by experts to be one of the emblematic aspects of ongoing climate change, characterized by a constant and widespread temperature rise in almost all seasons. The result is an extension of the warm season at the expense of normal seasonal balances, with summer-like conditions extending into the meteorological autumn. The temperature anomalies forecast for these days are indeed reaching positive deviations of 3-4 degrees above the norm across much of the country, with even higher peaks in some regions.