Refining Nigeria’s climatic zones for sustainable building design applications

Accurate climate classification is crucial for designing energy-efficient and sustainable buildings, particularly in countries with diverse and complex climate conditions, such as Nigeria. While widely adopted global categorizations, such as the Köppen-Geiger and ASHRAE climate classifications, offer general guidance, they often fall short in capturing localized variations and moisture-related parameters that are critical to design decisions. This study proposes a refined climatic zoning framework for Nigeria by integrating Wet Bulb Degree Days (WBDD) with conventional thermal indices such as Cooling Degree Days (CDD) and Heating Degree Days (HDD). Using data collected from 48 meteorological stations across Nigeria between 2009 and 2023, the study identifies seven distinct climatic zones with improved boundary definitions, departing significantly from ASHRAE’s broad classification of most of Nigeria as ‘‘extremely hot and humid.’’ Notably, Jos is reclassified as ‘‘warm’’ rather than ‘‘hot,’’ while Lagos emerges as ‘‘very humid’’ based on elevated WBDD values. These findings emphasize Nigeria’s climatic heterogeneity and offer a more practical basis for passive design strategies, climate-responsive architecture, and energy policy. By integrating localized climate data, the study supports improved building performance and enhanced thermal comfort and contributes to achieving Sustainable Development Goal 7 (Affordable and Clean Energy).