Burundi’s climate is largely controlled by the Inter-tropical Convergence Zone (ITCZ), which brings rain to Burundi as it moves southward. Additionally, the altitude of the country influences and modifies the climate on the local scale. The rainy season occurs during the months of October-May, which is interrupted by a short dry period in January, which lasts only 15 days. The dry season lasts from June-September and experiences the highest average annual temperatures, occurring from August to September (around 21°C). Mean annual rainfall ranges from less than 900 mm (e.g.,Imbo floodplain) to 1,600 mm (e.g., altitudes above 2,000 m). Mumirwa, Kumoso, Buragane, and Bugesera regions record average yearly temperatures between 21-13°C and rainfall between 1,000-1,300 mm per year. The central plateaus have average annual temperatures between 18-21°C and annual average precipitation between 1,200-1,600 mm per year. The Congo-Nile watershed experiences average yearly temperatures between 15.8-18°C and rainfall over 1,600 mm per year.
- Mean temperature has increased by 0.7-0.9°C since the 1930's.
- Since the 1980's, mean annual temperature in the southern and equatorial regions of East Africa has experienced a significant increase.
- A cyclical character of rainfall has been observed. It alternates between periods of rainfall surplus and periods of deficits. Inter-decadal variability operates on periods of around 10 years.
- Since 1999, the central plateaus region has seen an increase in seasonal variability with a tendency towards a longer dry season from, 5-6 months instead of the normal 4 (June-September).
This section provides the options to visualize historical climate data for different timeframes via map and annual cycle chart.