Chile - weather in December

In Chile, December is the first month of summer.

North

In the northern part of the coast, where we find the Atacama desert (see Arica, Iquique, Antofagasta), temperatures are pleasantly warm, with a daily average ranging from 19 to 21 °C (66 to 70 °C), the sky is usually clear (although mists and low clouds may form in the morning) and it never rains. The ocean in the northernmost part is a bit cool but overall it is acceptable for swimming.
In the inland areas of the north, occupied by a plateau and by the Andes (see Calama, San Pedro de Atacama), it's always sunny. The diurnal temperature range is very wide, and even though it is the warmest time of the year, it gets cold at night, and at the highest altitudes, above 3,000 metres (9,800 feet), the temperature can drop below freezing.

Center

In the central part of the coast (see Valparaiso, Viña del Mar), good weather prevails as well, but the temperature is quite cool (the daily average is around 18 °C or 64.5 °F), and the sea is also cold. In Santiago, in the inland areas of the center, the daily average is 20.5 °C (69 °F), but the temperature range is high, so nights are cool, while it can get very hot during the day.

South

In the south, the temperature is progressively cooler: the daily average ranges from 15 °C (59 °F) in Valdivia to 10 °C (50 °F) in Punta Arenas. Furthermore, while in the center and north it never rains in the summer, in the south it can rain even in this season. Actually, in the area of the southern fjords, west of the Andes, the rains are frequent and abundant even in this period.
In the far south, the wind often blows, increasing the feeling of coolness.
In the southern part of the Andes, which unlike the northern part is green, it can rain even in summer, moreover, at the same altitude the temperature is much lower, so much so that there are glaciers at fairly low altitudes.

In the Southern Hemisphere, December is the month with the longest days, and December 21 is the summer solstice. In the extreme south, the days last more than 16 hours.




See also: Chile, the weather in November - January
The climate of Chile