Moisture　transfer　in　building　envelopes　can　affect　the　internal　surface　temperature　of　the　envelopes　and　the　air-conditioning　energy　consumption.　Therefore,　this　study　aims　to　evaluate　the　effect　of　moisture　transfer　on　thermal　performance　of　exterior　walls.　In　this　study,　a　coupled　heat　and　moisture　transfer　model　was　proposed.　With　the　measured　continuous　outdoor　climate　parameters　for　four　hot　and　humid　regions　including　Haikou,　Qionghai,　Xiamen,　and　Guangdong,　this　model　assessed　the　impact　of　moisture　transfer　on　the　inner　surface　temperature,　the　peak　cooling　loads,　and　the　heat　from　walls.　The　results　showed　that　the　fluctuation　range　of　the　internal　surface　temperature　decreased　when　moisture　transfer　is　considered.　The　peak　cooling　loads　were　overestimated　when　moisture　transfer　is　ignored.　Besides,　the　total　heat　from　walls　was　underestimated　by　around　4%　in　the　cooling　seasons.　This　study　could　provide　basis　for　future　studies　on　moisture　transfer　characteristics　in　coastal　and　island　areas.　©　2020,　Springer　Nature　Singapore　Pte　Ltd.