Unlike hot deserts, characterized by high temperatures and scarce precipitation, cold deserts have low temperatures for much of the year, especially in winter. They also receive little annual precipitation, as the water that falls is in the form of snow, which contributes to their climatic characteristics.
In the case of Chilean Patagonia, this lack of precipitation is mainly due to the rain shadow effect created by the Andes mountain range. The mountain barrier acts as a climatic divide, with the west (Chilean Patagonia) receiving abundant rainfall and the east (Argentinian Patagonia) remaining dry. This rain shadow is the primary reason why eastern Patagonia has a desert climate.
Another factor to highlight is the intense and constant winds, known as "Patagonian winds," that blow mainly from the west and southwest, increasing evaporation and further reducing the moisture available in the soil. The winds also contribute to low temperatures, creating an even colder wind chill.
Lastly, the geographical location of Patagonia at the southern tip of the South American continent means that the entire area is constantly exposed to cold air masses from Antarctica. Temperatures in Patagonia can be quite low, especially in winter, when frosts and snowfalls are frequent in the higher and more exposed areas. This combination of low temperatures and low precipitation is what defines Patagonia as a cold desert.
While we have explained why Patagonia is a cold desert, it is important to remember that this is a vast territory with a variety of ecosystems and landscapes throughout the region, which also varies depending on whether you are on the Chilean or Argentinian side.
As mentioned earlier, the Andes act as a climatic screen, a phenomenon seen throughout Chile, but in the Aysén Region, it allows for areas with lush forests, such as in Queulat National Park, extensive pampas like in Patagonia National Park, or areas that share both landscapes, like in Cerro Castillo National Park.
The cold desert climate of Patagonia has a significant impact on the region's flora and fauna. Plants that inhabit these areas tend to be hardy and adapted to arid conditions, with species like coirón and low shrubs dominating the landscape. The fauna includes animals that have evolved to survive in an environment with scarce water resources and low temperatures, such as the guanaco, puma, and various bird species.
Prepare for Extreme Weather: Ensure you bring suitable clothing for low temperatures, including thermal layers, windbreakers, and waterproof gear, as the weather can change rapidly, so always be prepared.
Protect Your Skin and Eyes: Solar radiation is a serious concern in Patagonia due to the ozone layer hole over this part of the southern hemisphere. Therefore, it is essential to use high-protection sunscreen, UV-filter sunglasses, and a hat or cap to protect yourself from the sun and Patagonian wind.
Stay Hydrated and Well-Fed: This is crucial if traveling to Patagonia in the fall, as the cold air can dehydrate you quickly without you realizing it. Always carry water and energy snacks during your excursions, as outdoor activities in Patagonia can be physically demanding.