Study of Heat Island Effect and Urban Microclimate in Kano Metropolis Using Physical Measurements

The urban heat island effect, whereby urban areas exhibit higher surface and air temperatures than surrounding rural areas, contributes to increased energy demand, reduced thermal comfort, and elevated heat-related health risks. Kano metropolis, one of Nigeria's largest and most densely built cities in the North West geopolitical zone, is expected to exhibit significant urban heat island intensity due to its extensive impervious surfaces and limited urban greenery. This study characterises the urban heat island effect in Kano metropolis using systematic measurement of air temperature, surface temperature, and relative humidity at 24 fixed stations distributed across urban core, peri-urban, and rural reference zones. Measurements are collected continuously over 12 months using calibrated temperature and humidity loggers. Land surface temperatures from Landsat 8 thermal imagery are used to validate spatial patterns. Results indicate maximum nocturnal urban heat island intensity of 3.8 degrees Celsius during the dry season, with the commercial core of Kano registering the most elevated temperatures. Daytime heat island intensity is weaker due to the high solar reflectance of light-coloured mud building surfaces in traditional quarters. The study provides urban microclimate data for cooling load calculations and heat health risk planning in Kano State. Keywords: urban heat island, urban microclimate, Kano, surface temperature, thermal comfort