*2.2. Method*

According to the World Meteorological Organization [28,29] (WMO), climatological standard normals are defined as the averages calculated for uniform and relatively long period including at least three consecutive periods of ten years. The climatological standard normals are hence the averages of the climatological data calculated for the consecutive periods of 30 years. Our climatological study is based on the standard normal calculated for the 1961–1990 period. The obtained arithmetic mean was calculated (for temperature and rainfall) by using the following formula:

$$X = \frac{1}{n} \sum\_{i=1}^{1} \mathbf{1}\_{i}(x\_{i}),\tag{1}$$

where, *n* = year number.

Over the Conakry site, the climatological normal calculated for temperature and rainfall on the 1961–1990 period corresponds to the values of 26.5 ◦C and 3806.8 mm, respectively. These values are used to calculate corresponding anomalies.
