Trend Analysis of Rainfall, Temperature and Relative Humidity Using Non-Parametric Tests in the Tamale Metropolis of Northern Ghana

This study investigates the trends and variations in rainfall, temperature, and relative humidity over a 33-year period (1990-2023) in the Tamale metropolis, using data from the five (5) data stations of Ghana Meteorological Agency (GMeT). Statistical trend analyses were performed using the Mann-Kendall test, followed by the Theil Sen slope test, to assess the direction and magnitude of changes in annual, monthly, and seasonal patterns. Between May and August (raining season), increasing temperatures are observed in May and July. Minimum temperatures are observed for every month of the year. However, there were increasing rainfalls in March but decreasing in August and September. Relative humidity exhibited decreasing trends in all months except March. To overcome the consequences of these, there is need to develop heat-tolerant crop varieties, adjust planting dates and schedules, promote agroforestry practices and enhance pest and disease management techniques.