Abstract: In recent years, Haikou City has experienced frequent high-temperature weather. This paper analyzes the characteristics of high temperature weather and climate in Haikou City and its circulation background in the past 60 years. Discuss the changing characteristics of high temperature weather and the main influence on weather systems, in order to seek the ideas of high temperature weather forecast in Haikou City. Research indicates, the high temperature weather in Haikou City mainly occurs from May to July, followed by April, August and March, there are very few high-temperature weather in February and September, and almost no abnormally high-temperature weather in other months; In the past 60 years, the high temperature index of Haikou City has generally tended to increase slowly, and its trend rate of change is about 0.042 d/a. By defining the comprehensive judgment index of the monthly high temperature impact index, it shows that the high temperature impact is the largest in July, followed by June and May. Through the systematic analysis of the main effects of high temperature weather, it can be seen that. The western Pacific subtropical high, low-pressure trough, South Asian high, and offshore sea temperature changes have a significant impact on the high temperature weather in Haikou City; When a tropical cyclone generates and affects Haikou City, its impact on the subsiding airflow in the front periphery is also one of the main causes of the high temperature in Haikou.