The central region around Santiago enjoys a Mediterranean-like climate and can be visited all year round although in July and August (their winter) temperatures can get down to the single figures. The autumn colours in the wine regions in April are beautiful.
Patagonia and the remote southern part of the country is best visited between October and April with the high season lasting from December to February. It is important to note that even during the high season the weather in Patagonia is notoriously unpredictable and you can often expect to experience four seasons in one day! Although their summer (December to February) offers the best chance of good weather in this region, it is also the time of year when it is the windiest. The wind is ferocious in Patagonia!
The north of the country and the Atacama desert is extremely dry and stays sunny most of the year. During the winter months of May until August the temperature drops considerably at night.
The Lake District receives a lot of rain and is best visited during spring and summer (October to March).
Easter Island has a subtropical climate and is drier from November to February and wetter from March to October.