The northern part of Cameroon is reported to be vulnerable to climate change and heavily dependent on agriculture. However, few studies have considered the evolution of climatic data that influence agriculture. Existing studies are rarely based on field data. The assessment of precipitation has gained more attention than that of temperature. Few publications have addressed temperature dynamics, and this research contributes to closing that gap by studying the dynamics of three temperature parameters, namely, maximum, minimum and mean temperatures. Data from 1973 to 2020 were collected from weather stations located in three major cities in northern Cameroon: Ngaoundere, and Garoua, from the weather stations of the Agency for Aerial Navigation Safety in Africa and Madagascar (ASECNA); and Maroua, from the weather station of the Cameroon Civil Aviation Authority (CCAA). The study reveals that in Ngaoundere, the minimum temperature increased by 8.7% between 1987 and 2020 compared to 1973–1987. In Garoua, the mean temperature increased by 2.2% between 2003 and 2020 compared to 1973–2002, the minimum temperature increased by 13.3% between 1985 and 2020 compared to 1973–1984, and the maximum temperature decreased by -8.2%. In Maroua, the mean temperature increased by 3.6% between 2002 and 2020 compared to 1973–2001, and the minimum temperature also increased by 17.8% between 1990 and 2020 compared to 1973–1989; however, the maximum temperature decreased by -6.8% between 1988 and 2020 compared to 1973–1987. The results of this study will be used as the basis for forecasting future agricultural conditions.