An unseasonably warm February

An unseasonably warm February
(1 March 2009)

February 2009 was the warmest February since records began in 1884. The monthly mean temperature of 20.5 degrees recorded at the Hong Kong Observatory was 4.2 degrees higher than the normal for the years 1971 to 2000. The temperature of 28.3 degrees recorded on February 25 was also the highest daily maximum temperature for February. The monthly mean temperatures for the 10 warmest months of February are shown in Table 1.

The unusually warm February was attributed to a weak northeast monsoon. The cold air from the north seldom reached southern China. In Hong Kong, the occurrence of the warmer southerly winds originating from the ocean was about three times of normal.

This record-breaking temperature reflects to some extent the long-term warming trend in Hong Kong. During the past 50 years, the monthly mean February temperature at the Hong Kong Observatory has shown a rising trend of about 0.4 degrees per decade (see Figure 1).

Table 1: Monthly mean temperatures for the 10 warmest February months recorded at the Hong Kong Observatory Headquarters

Figure 1: Trend of the monthly mean temperature of February recorded at the Hong Kong Observatory Headquarters in the past 50 years (1960-2009)