The climate of Comoros is characterized by a tropical climate with a rainy season that lasts from mid-November to mid-April and a dry season that extends from June to October. Annual rainfall ranges between 1,000 and 5,000 mm across the three islands due to differences in altitude and winds. Generally, the western regions of the islands experience the highest rainfall totals due to greater exposure to the monsoons. The rainy season, which extends from November to April, is characterized by hot and humid weather with frequent storms, including tropical cyclones that are concentrated between the months of January to April. Average temperatures hover around 27°C and average monthly precipitation ranges from 200-250 mm. From June to October, the dry season brings lower humidity and the lowest temperatures of the year, ranging between 18-28°C, with average temperatures around 24°C. Average precipitation during this time ranges between 50-100 mm per month.
- Average annual temperature in Comoros has increased by 0.9°C. The largest increase in temperature is during the rainy season, particularly the months of March to May.
- The rainy season has experienced increasing irregularity, but overall, it has shortened in duration from 6 months to around 3 months. During 1960-1975, Comoros experienced a decrease in precipitation, followed by a sharp increase in rainfall in 1976, and then followed by increased irregularity between 1977-1989.
- A lengthening of the dry season has been observed as well as a delayed onset of the rainy season.
- Prolonged drought has been observed in the late 1990's and early 2000's.