What causes Ecuador’s wet and dry seasons?

Ecuador’s wet and dry seasons are determined by different climatic factors depending on the region:

• The Costa (Coastal Region): Seasonal variations here are primarily driven by the movements of the intertropical convergence zone and the influence of the cold Peru Current. Generally, the region experiences a wet season during the first half of the year and a relatively dry season in the second half.1
• The Sierra (Highlands): Rainfall in the highlands is linked to the equinoxes. The region experiences a long dry season from June to September and a shorter dry season, known as the veranillo, from December through January.1
• The Oriente (Eastern Region): This area is influenced throughout the year by an unstable maritime tropical air mass, resulting in fairly continuous and abundant rainfall.1

Additionally, the El Niño phenomenon can significantly disrupt these patterns. During El Niño years, warm water collects off the coast, which can lead to torrential downpours and unseasonable weather across the country.12