Natural conditions 1.weather: The annual rainfall is between 849.1 to 2211.2 mm ,average annual rainfall is1,664 mm, mainly concentrated in July to September, mostly thunderstorms , and obviously affected by typhoons. Annual fog days is 13.2 days, mainly in spring, the fog happens generally from 2 a.m to 9 a.m, mostly advection fog, visibility ranges from 100 to 800 meters. Beihai Port’s climate belongs to subtropical maritime climate, the annual average temperature is22.6°C, the highest temperature through over the years is 37.1°C and the lowest temperature is 2°C. 2.Hydrological It belongs to a mixed tide type based on the irregular diurnal tide. The tide flood season is diurnal tide with an average of 22 days a month. The neap flood season is semidiurnal tide with a monthly average of 8 days. The highest tide level is 5.55 m, the lowest is 0.03 m, maximum tidal range is 5.36 m, the minimum tidal range is 0.17 m, the average tidal range is 2.55 m.