Since 1980, temperature increases in the three metropolitan areas of Taipei, Taichung and Tainan have been around two times higher than those in three medium and smaller cities (Hualien, Taitung and Hengchun). This shows that metropolitan areas are being more seriously affected by HIE.
首先，1980 年以後，在台北、台中、台南 3 大都會區的增溫比 3 個中小城（花蓮、台東、恆春）高出約 2 倍（前者增幅約 0.8 ℃，後者約 0.4 ℃），顯示都會區熱島效應最為嚴重。