中文摘要：

利用1971—2000年楚雄市和大理市的气温、降水、相对湿度、平均风速等气候资料，分析了楚雄市和大理市两城市热岛效应变化特征，应用灰色关联度方法分析热岛强度发生变化的原因。结果发现：30年来楚雄市的热岛强度年变化在不断增强，而大理市热岛强度增加不如楚雄市明显，热岛强度月变化两城市基本一致，干季强，雨季弱；热岛强度日变化楚雄夜间强白昼弱，大理市清晨强，黄昏弱。

英文摘要：

The urban heat island changes in Chuxiong and Dali, two cities on the Yunnan plateau, are studied and compared with the data of air temperature, precipitation, relative humidity, average wind speed and so on from 1971 to 2000. The grey correlation degree is used to explain the causes of changes. The results indicate that the intensity of urban heat island is increasing gradually in Chuxiong in recent thirty years, while the increase in the Dali is less obvious; the monthly changes of urban heat island intensity in the two cities are basically the same： strong in dry season,weak in rainy season; the heat island intensity is strong in the daytime and weak at night in Chuxiong,but strong in the early morning and weak in the early evening in Dali.