As for the climate, annual rainfall ranges from 1,500 mm on the Eastern side of the mountains to 700 mm in the Western lower areas, where the Segre and Lavansa valleys are the most protected against maritime winds. Snow is present here for approximately six months of the year in the highest areas. The average annual temperatures fluctuate from 11º C in the lower parts of Alt Urgell (Spain) to 0º C at the highest peaks. Winters are in general very cold and temperatures can go below -20º C. Summers aren't very warm.
Vegetation and fauna of the cadi-Moixeró natural Park si of particular interest for its contrasting altitudes and varying climatic conditions witch in turn favour a wide variety of plant-life ranging from artic species, to central European alpine species, to mediterranean ones, and all of them within the same territory.
Among all the mammals in the Park, the high mountain goat like antelope, the chamoi (Rupicapra rupicapra) stands out for its large population there. The red deer (Cervus elaphus) and the roe deer (Capreolus capreolus), have been reintroduced and are now multiplying themselves again. Another interesting mammal is the pine martin (Martes martes) inhabiting in the majority of subalpine woods.
Birds of particular interest are the species that have survived since the glacial period, as capercaillie (Tetrao urogallus), tengmalm's owl (Aegolius funereus) and black woodpecker (Dryocopus martius), - the latter being the symbol of the Natural Park.
As for the reptiles, two interesting and colourful species are the green lizard (Lacerta viridis) and the Western whip snake (Coluber viridiflavus). Amongst the amphibious animals, the Pyrenean brook salamander (Euproctus asper) an endemism of these mountains, and the common or grass frog (Rana temporaria).