Historical climate information plays significant role in facilitating the contextualization and interpretation of future climate projections. Climate variables (temperature and precipitation) can be analyzed at various levels, in terms of trends, seasonality, and spatial variability. Key historical climate trends include:
- Average yearly temperature has increased around 1°C.
- Observations suggest a shortening of the cool season during the months of December-February to only two months, December and January. Average annual temperature in the region of Bafata has increased by 0.3° C over 1961-2003.
- Observations of mean annual precipitation indicate that precipitation has decreased over the period of 1961-1990.
- Meteorological station data in eastern Guinea-Bissau indicate decreasing precipitation trends during the rainy season (May-October) and dry season (December-April), over the period of 1951-2000.
- A late start to the rainy season has been observed; now beginning around mid-June instead of early May. The dry season has extended in length, particularly in the eastern regions of the country.
This section provides the options to visualize historical climate data for different timeframes via map and annual cycle chart.