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climate change

Climate Change in Hong Kong

<<Temperature

Rainfall

Mean sea level>>

The annual total rainfall at the Hong Kong Observatory Headquarters rose at an average rate of 39 mm/decade from 1947 to 2016, though statistically insignificant at 5% level. The annual rainfall trend is small compared to the year-to-year fluctuation.

annual rainfall at the HKO headquarters from 1947 to 2016

Annual rainfall at the Hong Kong Observatory Headquarters (1947-2016)


» Rainfall data

 

Rainfall over different regions of Hong Kong was generally on a rising trend. The increasing trend was higher in the urban areas than the New Territories, offshore islands and high grounds. Urbanization is one of the possible causes for the increasing trend and regional variation of rainfall in Hong Kong. Higher temperature in urban areas enhances convective activities and the increase in concentration of suspended particulates from urban activities favours the formation and development of rain-bearing clouds.

 


Heavy Rain


The frequency of occurrence of heavy rain events has increased slightly after World War II. The annual number of heavy rain days (days with hourly rainfall greater than 30 mm) increased at an average rate of 0.3 days per decade from 1947 to 2016.

Number of heavy rain days recorded at the HKO headquarters from 1947 to 2016.

Number of heavy rain days (days with hourly rainfall > 30 mm) recorded at the Hong Kong Observatory Headquarters (1947-2016).