The climate in Ischia can be defined as temperate-warm, with moderate winter and summer mean, soft daytime, monthly and annual excursions, thermal uniformity and remarkable dryness. The annual periodic excursion (difference between the extreme monthly averages) is 14.6° C. Island temperatures are slightly higher on the southern slopes.
Rainfall averages are higher on the northern slopes, ie the Northeast and North slopes. They vary from 700 mm annually to rain at S. Angelo, to 1050 mm at Buceto. On Mount Epomeo and nearby locations more than 500 m, it is snowing almost every year in the months of January-February.
The highest values of absolute humidity are in July and August (15.4-15.6) and the lowest in January and February (6.5-6.6). The annual average relative humidity is 67%. Ischia Porto is the north-east slope affected by the north-west wind, the maestral, in the months of March-October, while the south-east (south-east) prevails from September to December. From January to March the tramontana blows. The Punta Imperatore station finds that the south and south-east slopes are affected in the spring, summer and autumn by the spring and winter from the tramontana.