The climate in the Galapagos islands, though under the equator, cooled by the Humboldt current, and is characterized by two main seasons: (1) the warm, wet season (January to April), and (2) the cool, dry season (May to December). December to May is the best season for visiting the islands when the weather is pleasantly warm and the winds are 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. Heavy rains in the upper elevations send streams of water down the slopes to even the lowest island points.
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. During this period, rain is scarce on the coastal regions. Only plants that can survive long periods of time without water -- such as lichens and cacti -- thrive in these areas. Higher up, however, clouds of moisture support the thick vegetation