The climates of the Eastern Pyrenees: from the lands of Girona to Northern Catalonia and Andorra

Abstract

The predominant climate in the Eastern Pyrenees is the Mediterranean-influenced Pyrenean climate. Average annual temperatures range between about 10º C and just below 0º C, which are slightly higher, in general, than corresponding temperatures on the Atlantic slopes. Average annual precipitation varies from under 600 mm to over 1400 mm, while the number of snow-covered days oscillates between about six and over eighty (depending on location). Summer is generally the wettest season, whilst winter is the driest. Precipitation (and, more specifically snow) is of less importance than in the case of Atlantic-influenced Pyrenean climate.

The Mediterranean-influenced Pyrenean climate predominates on four slopes: Southern, Eastern, Southwestern and Southeastern facing. On the first (Upper Aude basin) some characteristics of Atlantic-influenced Pyrenean climate can be distinguished (minimum seasonal precipitation in summer in the southernmost sector). On the Eastern slopes, Mediterranean influences are marked, but unequally distributed. The Canigó mountain peak divides these slopes in two sections of unequal precipitation: the Tet basin, where precipitation is slight, and the Tec basin, where precipitation is abundant.

It is only on the Southwestern slopes (Upper Segre basin), which are the most extensive in the Eastern Pyrenees, that clear indications of aridity exist in certain sectors. This characteristic is a result of the rain-shadow effect caused by the two Pyrenees mountain chains in the area. Finally, the most marked Mediterranean influences are experienced on the Southeastern-facing slopes (Upper Llobregat and Ter-Freser basins). Summer precipitation frequently exceeds 300 mm as a result of dynamic modifications to the humid Mediterranean airmasses, so persistent in summer, as they rise over these slopes.