Summer　sol–air　temperature　(tsa)　is　a　basic　parameter　required　for　building　cooling　load　calculation,　which　is　a　comprehensive　performance　of　heat　radiation　and　outdoor　air　temperature.　And　the　value　is　determined　by　the　total　heat　transfer　coefficient　(αw)　on　the　wall　exterior　surface.　The　code　for　thermal　design　of　China　stipulates　that　αw　equals　19　W/m2·℃,　which　ignores　the　correction　on　convective　heat　transfer　coefficient　(αc)　affected　by　prevalent　wind　speed　in　different　climate　zones　and　the　evaporation　heat　transfer　coefficient　(αv)　caused　by　rainfall.　To　address　this　issue,　a　case　study　was　conducted　on　an　island　building　in　China.　The　value　of　αc　at　high　wind　speed　(4.2 m/s)　was　corrected,　and　the　hourly　value　of　αv　on　the　humid　wall　surface　was　supplemented.　The　results　show　that　due　to　the　correction　of　αw,　tsa　decreases　by　an　average　of　3.35　℃　on　the　vertical　and　8.34　℃　on　the　horizontal.　©　2023,　The　Author(s),　under　exclusive　license　to　Springer　Nature　Singapore　Pte　Ltd.