The climate that characterizes the Region of Aysén is the cold oceanic climate of low temperatures, with abundant rainfall, strong winds and high humidity. The characteristics of the relief cause a difference of climates in the eastern sector, formed by islands and archipelagos, and in the eastern sector of the Patagonian Cordillera.
Aysén has the best and most important of Chile’s river trout fishing basins, hundreds of lakes (one of them, General Carrera Lake, is the second largest in South America), lagoons, and mountain streams, all with abundant numbers of brown and/or rainbow trout. It has a diverse entomology, with mayflies, caddises, and dragonflies and damselflies, as well as large populations of important terrestrial insects. The impressive geology and numerous river and lake systems with excellent fish populations and insect hatches combine to make this region a fly fisher’s paradise.
The Western Patagonia was a distant and inhospitable for explorers who ventured into their cold lands region. The coastal zone , dismembered in multiple archipelagos, channels and maritime entrances, eternally rainy and covered with thick jungle, contrasts with the large and arid plateaus of the interior, whipped by strong winds and without vegetation than grasses. The Andes mountain range bifurcates into multiple branches, cut by glacial valleys and rivers that rise in the steppe to fall to the Pacific Ocean, such as the rivers Aysén, Simpson, Swans, and Baker rivers , through which drain the lakes General Carrera and Cochrane. In the southern part of the region, there are two giant ice plateaus that drain through glaciers in marine or lacustrine waters.