Located in subtropical area, Beihai enjoys a monsoon maritime climate. The major feature of the climate is mild and humid without bitter cold in winter and oppressive heat in summer. The seawater has a warm temperate on average. People can swim here in spring, summer and autumn. Therefore, the best time for visit is from April to November.
What's worth mentioning is that every cubic centimeter of air contains over 2500-5000 negative oxygen ions, 50-100 times that of inland cities. Consequently, Beihai can be dubbed as "a free Oxygen Bar". Beihai has an annual average temperature of 22.9℃. The hottest month falls in July within a maximum temperature of 37.1℃ and the coldest month is January with a minimum temperature of 2℃. Annual rainfall volume can reach to 1670mm and annual average of sunshine duration is 2009 hours. The main disaster of Beihai is typhoon, which usually takes place from June to August and 6 times annually.