Chilean Climate Zones: From Arid Deserts to Polar Regions
Arid North
1. Coastal Desert Climate
This climate is located on the coastal strip between Arica (Region I) and Quintero (Region IV). It’s influenced by the Pacific anticyclone, inhibiting rainfall, with prevailing winds from the south and southeast. Rainfall is insignificant, averaging 1 mm in Arica, 2 mm in Iquique, 8 mm in Antofagasta, and 27 mm in Caldera.
The temperature is moderate and homogeneous. Iquique’s average is 17.9°C, with extremes of 20.9°C in January and 15.4°C in July and August.
The camanchaca fog is responsible for a weak xerophytic vegetation cover.
2. Normal Desert Climate
Located in the central depression from Region I to Region III. Notable features include a clear atmosphere, strong temperature range, and an almost total lack of rainfall, with downpours every 5-6 years.
It’s a hot desert with high altitudes in the interior plains, resulting in average monthly temperatures mostly below 18°C.
3. Marginal Desert Climate
Between Copiapó and Vallenar, this climate presents increased humidity and precipitation (Copiapó: 30 mm; Vallenar: 65 mm). Temperatures average 16.3°C in Copiapó and 12°C in Vallenar.
4. High-Altitude Desert Climate
Located in the Andes Mountains in the North at altitudes above 2,500 meters, spanning Regions I to III. Rainfall is higher than in western climates but insufficient for a stable, seasonal vegetation environment.
5. High Steppe Climate
Associated with the high-altitude desert, this climate has higher rainfall (about 350 mm per year), with summer rains, minimum temperatures below 0°C at night, and very cold winters.
Semi-Arid Climates of the Norte Chico
1. Coastal Steppe Climate
Located in the coastal sector between Zapallar and Elqui (Regions IV and V). It’s characterized by increased rainfall compared to the Far North (about 100 mm) and high humidity, expressed in fog and drizzle, which constitute an important mode of precipitation.
La Serena has an average annual temperature of 14.7°C with a low oscillation of 7.6°C.
2. Interior Steppe Climate
Located in the valleys and middle hills of Regions III and IV, from Vallenar to the Aconcagua River Basin. It’s a climate of clear skies, low humidity, and higher temperatures than on the coast.
Temperatures are moderate with significant daily fluctuations (19°C to 20°C). The sunny, dry weather in the high valleys favors astronomical observatories like Tololo near La Serena and La Silla and La Campana near Vallenar.
Climates of Central Chile
1. Temperate Mediterranean Climate with Long Dry Season
Located between Regions V and VII, from the Aconcagua River to the Maule River basin. It has a long dry season (7 to 8 months).
Temperatures have large daily fluctuations in the Intermediate Depression, attenuated in coastal regions. Valparaíso has a thermal amplitude of 6.2°C, while Santiago has 11.9°C.
Rainfall also varies: Valparaíso records 460 mm annually, while Santiago receives 356 mm.
2. Temperate Mediterranean Climate with Dry and Wet Seasons
Located between the Maule River and near Traiguén. It has equal dry and wet seasons (6 months each).
Characterized by high rainfall, generally exceeding 1000 mm annually.
High summer temperatures are a thermal singularity. Chillán has higher temperatures in January and February than Santiago.
Concepción has average annual temperatures of 13°C and a reduced amplitude of 8.9°C due to strong maritime influence.
Climates of Southern Chile
1. Temperate Rainy Climate
Located in Regions IX and X, from the Cautín River Basin to the north of Puerto Montt.
Characterized by year-round rainfall, although summer months have less rain than winter. Temuco records 1,345 mm, and Valdivia records 1,184 mm.
Temperatures have little variation by latitude, with low oscillations. Puerto Domínguez has an annual average of 11.4°C and a fluctuation of 6.6°C.
2. Maritime Rainy Climate
Extends from Puerto Montt to the Taitao Peninsula.
Rainfall is abundant, increasing southward, reaching over 2,000 mm. Puerto Aysén has an average annual rainfall of 2,940 mm.
Temperatures are rather low, decreasing southward (Puerto Montt 11.2°C, Melinka 10°C). Maritime influence provides weak annual temperature variation (Guafo 5.2°C, Puerto Aysén 8.8°C).
3. Cold Temperate Rainy Climate with Strong Maritime Influence
Located south of the Taitao Peninsula, on the maritime side of the mountains and the Patagonian archipelago, extending inland along river valleys. Its southern limit is the Strait of Magellan.
In northern sectors, only four months have temperatures above 10°C, and thermal averages decrease southward. The average annual temperature is 8.2°C. Sheltered positions have three months with temperatures above 10°C, with August being the coldest month at 5.5°C.
4. Cold Steppe Climate
Lies in the Andean sectors of Region XI from 44° latitude south and the mountain range and plains of Region XII.
Polar Climate
The true polar climate occurs in the Chilean Antarctic Territory. Solid precipitation (snow) and blizzards predominate. It’s characterized by temperature fluctuations under 8°C in an extremely inhospitable landscape. The lowest monthly average temperature recorded at the O’Higgins Base is -12.7°C in July. Rainfall at the same station is 1,200 mm.