This book describes observed features of urban climate and its long-term variations as well as the relationship of climate to heat stroke in Japan, based on observational data and statistical analyses. Consisting of three parts, the book is a valuable resource for researchers and professionals involved with these topics. Part 1 focuses on urban climate. The basic characteristics of heat islands are reviewed, and long-term urban warming is described with a focus on the distinction from global warming. The influence of microscale environmental changes on the observed temperature is also presented, as well as changes in wind and precipitation in urban areas. They deepen our understanding of the features and mechanisms of urban heat islands and their long-term changes. Part 2 describes the climatological features of heat stroke mortality, which has become a major social problem in Japan, using mortality statistics and meteorological data. The spatial and temporal variations of heat stroke mortality are analyzed quantitatively on various spatial and temporal scales. In addition, the number of ambulance transports is examined as another measure of heat stroke casualty. The results provide insight into the climatological factors related to heat stroke mortality and contribute to the implementation of preventive measures. The climatology of deaths from extreme cold is also presented. For supplementary information, an overview of the geography, climate, and meteorological data of Japan is presented in Part 3.