Temporal Characteristics and Long-Term Trends of Harmattan Meteorological Variables in Gombe State, Northeastern Nigeria (1996–2025)

The Harmattan season is a defining climatic phenomenon across northern Nigeria, influencing environmental quality, public health, transportation, and agricultural productivity. This study examined the temporal characteristics and long-term trends of Harmattan meteorological variables in Gombe State, Nigeria, using thirty years (1996–2025) of meteorological observations. We analysed five key variables, visibility, wind speed, relative humidity, maximum temperature, and minimum temperature, using descriptive statistics, seasonal analysis, and linear regression. Results revealed considerable interannual variability in all meteorological parameters. Mean visibility was 927.45 m, wind speed averaged 6.73 m s⁻¹, relative humidity averaged 21.81%, while mean maximum and minimum temperatures were 31.53°C and 16.69°C, respectively. Seasonal analysis indicated strengthening winds and declining humidity from November to February, with January representing the peak Harmattan period. Trend analysis showed increasing but statistically insignificant trends in visibility, wind speed, and temperatures (p > 0.05), whereas relative humidity exhibited a significant decreasing trend (slope = –0.31; p = 0.0054). The findings suggest that progressive atmospheric drying is the dominant long-term climatic signal affecting Harmattan conditions in Gombe State. At the same time, year-to-year variability continues to control dust transport and visibility. The study provides valuable evidence for climate adaptation planning and environmental management in the Sudano-Sahelian region.