Changes in the seasonal cycles of extreme temperatures in the Sudano-Sahelian domain in West Africa: a case study from Burkina Faso

Temperature is a key variable in understanding climate change. In tropical West Africa, however, temperature has been neglected because it is always hot because of the sun. Studying extreme temperatures can be a way to better understand climate change in the Sudano-Sahelian region of West Africa. The main objective of this study is to analyze changes in extreme temperatures. To this end, temperature data were obtained from Power NASA over the period 1981-2022 at monthly time steps. The methods used to analyze the data were normality and homogeneity statistics, linear regression, Mann-Kendall tests, and Spearman’s r test. Tests of Sen’s slope estimator, moving averages, and z-score. The study shows that maximum temperatures are normally distributed, unlike minimum temperatures, and that maximum temperature data are homogeneous, with breaks in the periods 1998, 2000, 2006, and 2010 before, during, and after the rainy seasons. On the other hand, minimum temperature data are generally not homogeneous and do not show many breaks. The study also shows that extreme temperatures tend to increase before, during, and after the rainy season, according to Spearman’s r test. However, the Mann-Kendall test shows that extreme temperatures generally do not show trends. Furthermore, temperatures are continuously variable, with an increase in temperature anomalies in the 1980s, 2000s, and 2020s.