Analysis of Harmattan Dust Haze Frequency and Intensity Over Kano Metropolis

Harmattan dust haze episodes represent a recurrent meteorological hazard across Nigeria's North West zone, significantly impairing air quality, visibility, and human health. This study analyzes the frequency, duration, and intensity of harmattan dust haze events over Kano Metropolis using surface meteorological observations from Mallam Aminu Kano International Airport weather station for the period 2019 to 2023. Descriptive statistical methods were applied to daily horizontal visibility records, while synoptic weather charts sourced from NiMet were used to characterize the atmospheric circulation patterns associated with intense haze events. The study further documents community health responses through structured interviews conducted with 150 residents across selected neighborhoods. Results indicate that severe haze events, defined by visibility below 1,000 metres, occur an average of 28 days annually, with peak frequency recorded in December and January. An increasing trend in haze duration over the five-year study period is observed, consistent with documented desertification pressures in the Sahel region. Health impact assessment reveals heightened incidence of respiratory and ophthalmological complaints during peak haze periods, disproportionately affecting outdoor workers and school-age children. The study recommends the expansion of real-time particulate matter monitoring infrastructure in Kano and the formulation of a public early warning system linked to haze intensity thresholds. Keywords: harmattan, dust haze, Kano, visibility, air quality.