Chile is a mostly midlatitude country whose seasons are the reverse of those in the Northern Hemisphere. In general, Santiago's mild Mediterranean climate resembles that of California, with a long dry spring and summer (September or October-April) and a wetter winter (May-September). Annual rainfall averages around 14 in/36 cm. Temperatures rarely fall below freezing in winter, and snow is uncommon (except, of course, in the nearby Andes). Summers may reach 95 F/36 C, but the city's altitude (about 2,000 ft/600 m above sea level) means it almost always cools off at night.
Santiago is truly a year-round destination with even winters being very mild. However, a lack of wind during winter can result in increased pollution unless rainfall is frequent. This is of of particular concern to people with respiratory conditions or young children.