The Galapagos Archipelago has a sub-tropical climate that allows cruises to operate year-round.

Temperatures are determined almost entirely by the ocean currents that are influenced by the trade winds. There are two main seasons:  January to April is the warm, wet season and May to December is the cool, dry season. December through May are the best months for visiting the islands because the weather tends to be pleasantly warm and the winds light. The rainy season, which lasts from January to April, is marked by decreased winds and warmer sea currents. The days are warm and the seas are calm during these months. From June to November the weather is overcast and cool. The water around the islands is surprisingly cold and the meeting of the Humboldt current and the warm air sometimes causes mist over the islands. Occasionally the Humboldt current is replaced by the warm El Niño current, a phenomenon which can affect weather conditions throughout the South Pacific. From May to December, when the winds blow in a southeasterly direction, the shores of the southern islands are bathed in cool waters, chilling the air and creating unusually cold conditions for equatorial islands.