The Carretera Austral extends from approximately 41°S to 49°S, and as such suffers cold and extended winters (June–September) and surprisingly warm summers (December–March). Hours of daylight in Coyhaique, approximately midway along the Carretera, range from 9 hours in June to 15 hours in December. Snow is less common on the western side of the Andes, but precipitation is notably higher in winter. However, the coastal region of the Carretera is notoriously wet throughout the year. Puerto Cisnes suffers approximately 4,000mm of annual rainfall.
The peak summer season, when most tourists visit, is January and February, when most of the festivals take place. It can be hard to book ferries in these months, and hotels fill up, so it is worth booking in advance. The ideal time to visit is possibly from mid-October until the end of the year, or in March or April when the Chilean school holidays end, as during this time there are fewer tourists, less traffic, lower prices and decent weather. October and April are the earliest and latest times when the Carretera is readily accessible and the majority of businesses are open, although increasing numbers operate year-round. In the low season, transport connections, including ferries, are fewer and some businesses simply close.
The Carretera Austral has four distinct seasons. The summer begins in December and extends into March, although January and February are the most popular months to visit, coinciding with Chilean school holidays. Temperatures exceed 20°C in summer, and very rarely 30°C. The winter extends from June to September, and temperatures routinely fall below freezing. The lowest recorded temperature in Coyhaique is –15°C. Rainfall is abundant across most of this region, with the wettest months generally being April to August, particularly on the western coast. Puerto Cisnes and Puyuhuapi receive inordinate amounts of rain, contributing in part to the lush vegetation of the region. However, there is no month in the year where a waterproof jacket is not useful. Southern Chile is one of the rainiest regions on the planet. Annual rainfall in Puerto Cisnes, one of the wettest regions, can reach 4,000mm compared with a mere 600mm/year in London. The driest month of the year in Puerto Cisnes, February, typically receives 120mm of rain, raining every other day.
As a general rule, rainfall is lowest in February, and further to the east: Lago Verde receives an average of only 6mm of rain (three days of rain), Coyhaique perhaps double this, and Futaleufú 42mm (five days of rain). Snowfall is actually limited in the region, but it is sometimes possible to ski at the small Fraile ski resort near Coyhaique in winter.
- 1 January – New Year
- Late March/early April – Easter
- 1 May – Labour Day
- 21 May – Navy Day
- 29 June – Sts Peter and Paul Day
- 16 July – Virgen del Carmen
- 15 August – Assumption of the Virgin Mary
- 18 September – National Day
- 19 September – Army Day
- 12 October – Colombus Day
- 31 October – Reformation Day
- 1 November – All Saints’ Day
- 8 December – Immaculate Conception
- 25 December – Christmas Day
Besides the usual holidays around Christmas and New Year, the main public holidays a visitor to the Carretera Austral is likely to witness are the annual celebrations of individual towns, often based around a rodeo theme, generally in January or February – the exact dates vary from year to year.