The climate in Abruzzo is strongly influenced by the great Appenine mountain range that cleanly bisects the region into a coastal, sub-Appenine hill area and a higher, mountainous area.
The first of these zones has a semi-Mediterranean climate whose temperatures steadily decrease and rainfall increases in relation to the altitude (at approximately 10m above sea level, for example, Pescara has an average temperature of 15.5°C and over 700mm of rain a year, while Chieti, at an altitude of 330 m, only just rises above an average of 13 °C but has higher annual rainfall of around 900-1000 mm)
The lowest rainfall occurs not along the coast but in the hinterland valleys that are very sheltered from bad weather, such as Val Peligna, which in some places sees barely 500 mm of rain a year. In these territories, particularly in Aquila and Marsica, there is often frost in the winter and in periods of high pressure the barometer can fall as low as 20 °C below zero.