The　combination　of　global　climate　change　and　the　urban　heat　island　effect　has　given　rise　to　a　deterioration　in　the　livability　of　residential　districts　within　cities,　posing　challenges　to　enhancing　the　health　quality　of　urban　environments.　Meanwhile,　the　intensification　of　daytime　changes　in　temperature　and　humidity　in　residential　districts　has　rendered　the　sensory　representation　of　the　urban　heat　island　effect　more　pronounced.　This　study　selects　the　residential　districts　in　Fuzhou　City　as　the　research　case　area,　which　have　witnessed　a　discernible　warming　trend　in　recent　years,　and　acquires　temperature　and　humidity　parameter　data　at　three　time　periods　(early　morning,　noon,　and　evening)　to　represent　the　daytime　temperature　and　humidity　change　phase.　Through　aerial　photography　and　field　research,　three　types　of　spatial　morphological　indicators　(buildings　I,　vegetation　II,　and　the　combination　of　buildings　and　vegetation　II)　of　residential　districts　are　quantified　to　represent　the　three-dimensional　spatial　form　of　the　case　study　area.　The　analysis　results　show　the　following:　➀　Residential　districts　experience　two　phases　of　daytime　changes　in　temperature　and　humidity:　a　warming　and　drying　phase　(WDP)　in　the　morning　and　a　cooling　and　humidifying　phase　(CHP)　in　the　afternoon.　The　characteristics　of　changes　in　temperature　and　humidity　show　a　spatial　correlation　with　each　other.　➁　The　impact　of　urban　three-dimensional　morphology　on　changes　in　temperature　and　humidity　in　WDP　is　minor,　whereas,　in　CHP,　it　is　influenced　by　Class　II　and　Class　III　indicators.　The　two　types　of　urban　morphology　exert　a　synergistic　regulatory　effect　on　changes　in　temperature　and　humidity.　➂　Vegetation　has　a　significant　regulatory　effect　on　temperature　and　humidity　variations　in　residential　areas　through　changes　in　its　three-dimensional　form.　Enlarging　the　area　of　individual　trees　while　reducing　their　canopy　volume　can　restrain　the　warming　and　dehumidification　of　residential　districts　and　promote　cooling　and　humidification.　In　contrast　to　only　planting　trees,　a　vegetation　configuration　combining　trees,　shrubs,　and　grass　can　bring　a　more　obvious　cooling　effect　to　residential　districts.　The　research　results　can　provide　a　reference　for　urban　planners　in　the　planning　and　design　of　residential　areas　as　well　as　the　optimization　and　improvement　of　urban　living　environments.　©　2025　by　the　authors.