Rainfall   Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Period of Record Mean monthly Total (mm) 244.0 161.7 184.5 178.7 171.6 162.2 158.3 176.2 170.2 194.3 255.5 288.9 1868-2010 (142yrs) Highest Monthly Total (mm) 818.6 1893 566.7 1910 528.3 1913 454.9 1900 386.6 1892 378.7 1954 527.3 1890 526.3 1878 440.4 1988 497.1 1942 521.5 1874 765.9 2006 Lowest Monthly Total (mm) 15.4 1997   6.3 2010   18.5 1912 16.6 1977 41.6 1997 21.8 2009 18.6 1997 18 1888 23.7 1994 10.8 2002 53 1981 62.5 1932 Highest 1 day Total (mm) 194.4 31 2003 159.3 04 1995 122.8 08 2004 102.4 27 2007 153.7 04 1990 121.1 05 1984 149.1 27 1941 133.9 7 2008 187.3 21 1988 91.4 08 1952 198.6 02 1995 512.4 02 1978 Mean Raindays 15 11 14 15 14 13 13 14 14 16 19 19 1891-2010 (120yrs) Maximum Raindays 26 1927 24 1964 23 1945 23 1970 23 1991 26 1899 20 several 23 1936 22 1986 23 several 24 several 26 several Minimum Raindays 3 1976 1 1983 3 1983 3 1963 6 1997 4 1981 6 several 5 1941 1961 3 1997 5 1991 11 1998 8 1920

	TEMPERATURE (°C)   Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Period of Record Mean Daily Maximum 30.1 31.1 31.5 31.7 31.6 31.3 30.9 30.9 30.9 31.1 30.6 29.9 1929 - 1941 1948 - 2008 ( 74 yrs) Mean Daily Minimum 23.2 23.5 23.9 24.4 24.7 24.7 24.5 24.4 24.2 24.0 23.7 23.4 24-hr Mean 25.9 26.5 26.9 27.3 27.7 27.7 27.4 27.3 27.1 27.0 26.4 25.9 Highest Temperature 33.6 27 1998 35.2 26 2010 36 26 1998 35.8 19 1983 35.4 01 2005 35 25 1985 34 17 1991 17 1997 34.2 17 1986 34.3 15 2000 34.6 29 2002 34.3 17 1982 33.5 16 2005 1984 - Mar 2009 (26 yrs) Lowest Temperature 21.2 28 1984 21.1 02 1984 20.2 14 2000 21.7 12 1993 21.2 04 1989 21.1 19 1992 20.5 03 1990 21.1 15 1990 21 10 1984 21.1 06 1989 21.3 28 1983 21.9 02 1983 25 1983

	RELATIVE HUMIDITY (%)   Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Period of Record Mean Daily Maximum 95.9 95.8 96.4 96.9 96.4 95.6 95.0 95.1 95.9 96.5 97.1 96.8 1929 - 1941 1948 - 2008 ( 74 yrs) Mean Daily Minimum 65.6 61.3 62.0 63.4 64.7 64.2 64.8 64.5 63.9 63.2 66.1 68.2 24-hr Mean 84.8 83.0 83.8 84.8 84.4 83.0 82.8 83.0 83.5 84.1 86.4 86.9 Lowest Minimum 48 15 1997 38 28 1990 39 06 1990 30 1990 39 19 1983 45 10 1990 19 2003 36 20 2003 38 27 1982 40 17 1986 37 14 1994 40 07 1991 43 02 1996 49 02 2007 1984 - 2009 (25 yrs)

	SURFACE WIND   Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Period of Record Mean Wind Direction N/NE N/NE N/NE Variable S/SE S/SE S/SE S/SE S/SE Variable Variable N/NE 1935 - 1941 1948 - 2008 ( 68 yrs) Mean Daily Wind Speed (m/s) 2.4 2.4 1.8 1.3 1.3 1.6 1.9 1.9 1.6 1.3 1.3 1.8 Highest 10 minutes Mean Wind Speed (m/s) 12.2 6 1986 12.4 17 1977 14.2 3 1986 13.4 11 1981 13.9 6 1976 12.4 20 1978 15.4 5 1975 13.9 6 1979 13.9 19 1980 12.4 26 1976 13.8 10 1976 11.1 17 1981 1975 - 2008 (34 yrs)

	THUNDERSTORM, LIGHTNING   Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Period of Record Mean Thunderstorm Days 5 5 12 19 19 15 14 13 15 18 19 12 1982 - 2008 (27 yrs) Maximum Thunderstorm Days 13 2001 14 2000 23 2000 26 several 24 2001 21 1999 23 2004 20 1996 20 1986 1996 24 1993 26 1982 22 2000 Minimum Thunderstorm Days 0 several 0 several 3 1990 10 1990 10 2003 9 1982 4 1994 5 1988 4 1994 7 2006 14 1991 4 1986 Mean Lightning Days 6 5 14 22 22 17 14 12 14 20 24 16 Maximum Lightning Days 14 2000 14 1988 23 1985 28 1982 2003 29 1983 24 1988 25 1985 23 1996 24 1984 28 2001 29 1982 27 2002 Minimum Lightning Days 0 1986 1 several 2 1983 9 1983 13 2003 10 2004 1 1994 2 1997 0 1997 2 2006 14 2004 6 1983

Weather records from a climate station are compiled over long periods for the purpose of determining climatic trends. For this purpose, NEA uses the Changi climate station as a reference point.