ALTON stat,

Monthly Extreme Maximum Temperature (Degrees Fahrenheit)

(420086)

File last updated on Apr 4, 2013
*** Note *** Provisional Data *** After Year/Month 201302
a = 1 day missing, b = 2 days missing, c = 3 days, ..etc..,
z = 26 or more days missing, A = Accumulations present
Long-term means based on columns; thus, the monthly row may not
sum (or average) to the long-term annual value.
MAXIMUM ALLOWABLE NUMBER OF MISSING DAYS : 5
Individual Months not used for annual or monthly statistics if more than 5 days are missing.
Individual Years not used for annual statistics if any month in that year has more than 5 days missing.
YEAR(S) JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN
1915 ----- z ----- z ----- z ----- z 75.00 a 79.00 d 81.00 83.00 a 76.00 76.00 65.00 55.00 a 83.00
1916 46.00 a 59.00 65.00 75.00 78.00 85.00 84.00 77.00 74.00 64.00 67.00 50.00 85.00
1917 51.00 54.00 60.00 70.00 74.00 84.00 89.00 86.00 78.00 76.00 65.00 a 62.00 89.00
1918 63.00 57.00 62.00 70.00 77.00 94.00 82.00 93.00 d 82.00 76.00 66.00 57.00 94.00
1919 52.00 52.00 56.00 76.00 81.00 p 86.00 a 89.00 90.00 87.00 a 65.00 60.00 d 56.00 90.00
1920 64.00 53.00 60.00 68.00 79.00 87.00 87.00 85.00 a 80.00 74.00 60.00 a 51.00 87.00
1921 55.00 59.00 65.00 a 70.00 77.00 87.00 84.00 81.00 85.00 77.00 65.00 b 64.00 87.00
1922 52.00 49.00 57.00 a 65.00 78.00 85.00 b 90.00 83.00 79.00 a 73.00 58.00 d 56.00 h 90.00
1923 56.00 54.00 59.00 68.00 80.00 87.00 87.00 m 80.00 79.00 67.00 a 61.00 55.00 87.00
1924 49.00 61.00 52.00 66.00 80.00 86.00 85.00 86.00 89.00 70.00 67.00 53.00 89.00
1925 48.00 55.00 65.00 70.00 78.00 82.00 88.00 79.00 73.00 71.00 66.00 b 58.00 88.00
1926 55.00 a 60.00 a 66.00 a 71.00 a 77.00 a 87.00 86.00 82.00 78.00 a 77.00 b 70.00 57.00 87.00
1927 59.00 52.00 55.00 74.00 82.00 a 89.00 89.00 a 80.00 a 77.00 72.00 62.00 a 54.00 89.00
1928 55.00 a 50.00 64.00 74.00 80.00 80.00 87.00 84.00 a 80.00 e 75.00 b 58.00 b 52.00 87.00
1929 55.00 44.00 59.00 70.00 a 73.00 a 89.00 87.00 80.00 76.00 73.00 66.00 60.00 89.00
1930 45.00 58.00 56.00 76.00 67.00 a 86.00 84.00 a 80.00 80.00 69.00 67.00 50.00 86.00
1931 54.00 48.00 67.00 68.00 78.00 84.00 90.00 86.00 79.00 72.00 70.00 50.00 90.00
1932 40.00 50.00 a 57.00 69.00 76.00 84.00 86.00 83.00 81.00 71.00 65.00 54.00 86.00
1933 50.00 52.00 62.00 66.00 b 78.00 86.00 86.00 89.00 c 82.00 71.00 69.00 a 59.00 89.00
1934 55.00 63.00 69.00 74.00 82.00 86.00 89.00 88.00 84.00 78.00 70.00 55.00 89.00
1935 54.00 59.00 c 57.00 69.00 72.00 83.00 85.00 83.00 81.00 72.00 a 57.00 53.00 85.00
1936 51.00 57.00 56.00 76.00 c 79.00 90.00 a 85.00 c 84.00 79.00 a 77.00 64.00 49.00 90.00
1937 35.00 48.00 60.00 66.00 82.00 88.00 86.00 c 86.00 80.00 70.00 62.00 51.00 c 88.00
1938 48.00 41.00 50.00 a 72.00 80.00 81.00 85.00 87.00 78.00 68.00 52.00 61.00 87.00
1939 48.00 42.00 60.00 73.00 77.00 85.00 a 90.00 89.00 c 82.00 a 68.00 63.00 62.00 90.00
1940 52.00 50.00 67.00 72.00 a 76.00 90.00 89.00 90.00 84.00 70.00 a 61.00 62.00 90.00
1941 50.00 49.00 55.00 63.00 77.00 81.00 91.00 85.00 81.00 70.00 65.00 56.00 91.00
1942 52.00 46.00 57.00 67.00 81.00 84.00 90.00 88.00 84.00 77.00 66.00 59.00 90.00
1943 61.00 56.00 62.00 74.00 78.00 81.00 88.00 88.00 81.00 73.00 64.00 47.00 j 88.00
1944 51.00 53.00 53.00 60.00 73.00 84.00 86.00 87.00 84.00 72.00 60.00 57.00 87.00
1945 55.00 55.00 56.00 73.00 75.00 83.00 85.00 83.00 82.00 72.00 65.00 60.00 85.00
1946 50.00 56.00 60.00 75.00 75.00 85.00 86.00 85.00 80.00 69.00 57.00 55.00 86.00
1947 50.00 58.00 60.00 69.00 85.00 80.00 88.00 84.00 85.00 77.00 62.00 53.00 88.00
1948 53.00 54.00 53.00 70.00 78.00 82.00 88.00 88.00 88.00 70.00 58.00 50.00 88.00
1949 38.00 51.00 54.00 76.00 a 76.00 81.00 88.00 88.00 85.00 73.00 68.00 58.00 88.00
1950 51.00 57.00 67.00 72.00 81.00 92.00 90.00 91.00 90.00 81.00 72.00 65.00 92.00
1951 60.00 62.00 60.00 72.00 83.00 87.00 92.00 87.00 a 82.00 75.00 67.00 57.00 92.00
1952 55.00 53.00 55.00 67.00 75.00 80.00 86.00 87.00 84.00 80.00 66.00 58.00 87.00
1953 61.00 66.00 64.00 72.00 70.00 86.00 93.00 86.00 84.00 78.00 66.00 59.00 93.00
1954 60.00 63.00 63.00 75.00 80.00 94.00 90.00 94.00 85.00 75.00 73.00 56.00 94.00
1955 53.00 57.00 a 57.00 67.00 ----- z 89.00 91.00 91.00 91.00 77.00 69.00 54.00 91.00
1956 58.00 a 50.00 71.00 72.00 80.00 a 93.00 93.00 88.00 91.00 78.00 70.00 a 58.00 93.00
1957 52.00 b 65.00 60.00 66.00 76.00 88.00 90.00 90.00 88.00 76.00 62.00 60.00 90.00
1958 56.00 60.00 56.00 72.00 81.00 85.00 90.00 93.00 85.00 77.00 66.00 65.00 93.00
1959 61.00 53.00 59.00 a 78.00 83.00 90.00 a 95.00 87.00 87.00 82.00 63.00 61.00 95.00
1960 50.00 49.00 68.00 76.00 82.00 88.00 95.00 94.00 85.00 75.00 69.00 54.00 95.00
1961 60.00 59.00 65.00 74.00 81.00 95.00 94.00 89.00 77.00 76.00 63.00 52.00 95.00
1962 57.00 58.00 60.00 78.00 78.00 91.00 92.00 94.00 87.00 71.00 72.00 67.00 94.00
1963 57.00 65.00 62.00 69.00 81.00 84.00 93.00 94.00 a 83.00 82.00 66.00 63.00 94.00
1964 60.00 55.00 63.00 71.00 80.00 89.00 91.00 92.00 82.00 83.00 70.00 49.00 92.00
1965 56.00 59.00 62.00 74.00 76.00 81.00 86.00 88.00 77.00 83.00 67.00 58.00 88.00
1966 55.00 46.00 76.00 75.00 82.00 88.00 93.00 90.00 83.00 70.00 67.00 54.00 93.00
1967 55.00 60.00 62.00 63.00 82.00 85.00 90.00 88.00 83.00 73.00 68.00 51.00 90.00
1968 54.00 59.00 68.00 71.00 81.00 90.00 90.00 a 81.00 84.00 73.00 63.00 53.00 90.00
1969 58.00 50.00 64.00 73.00 82.00 82.00 88.00 a 90.00 88.00 75.00 63.00 59.00 90.00
1970 59.00 60.00 65.00 70.00 82.00 94.00 91.00 91.00 83.00 73.00 65.00 a 50.00 94.00
1971 60.00 62.00 68.00 71.00 74.00 90.00 93.00 89.00 87.00 76.00 61.00 47.00 93.00
1972 50.00 64.00 71.00 71.00 85.00 89.00 a 96.00 92.00 80.00 75.00 52.00 50.00 96.00
1973 54.00 50.00 48.00 69.00 81.00 91.00 92.00 89.00 83.00 76.00 68.00 51.00 92.00
1974 51.00 58.00 68.00 69.00 84.00 a 95.00 i 92.00 88.00 84.00 76.00 a 64.00 49.00 95.00
1975 59.00 56.00 58.00 63.00 77.00 85.00 89.00 89.00 83.00 77.00 71.00 57.00 89.00
1976 58.00 62.00 61.00 69.00 81.00 92.00 95.00 86.00 85.00 73.00 70.00 60.00 95.00
1977 56.00 65.00 62.00 77.00 83.00 91.00 91.00 92.00 89.00 75.00 69.00 62.00 92.00
1978 51.00 54.00 63.00 68.00 78.00 88.00 92.00 90.00 86.00 80.00 66.00 48.00 92.00
1979 45.00 52.00 57.00 69.00 80.00 89.00 91.00 91.00 87.00 83.00 59.00 64.00 91.00
1980 49.00 55.00 51.00 75.00 77.00 88.00 92.00 89.00 82.00 82.00 71.00 65.00 92.00
1981 60.00 b 63.00 59.00 81.00 80.00 a 93.00 90.00 93.00 89.00 71.00 66.00 59.00 93.00
1982 56.00 56.00 58.00 75.00 79.00 87.00 95.00 87.00 84.00 69.00 62.00 50.00 95.00
1983 55.00 54.00 58.00 63.00 86.00 84.00 88.00 85.00 87.00 72.00 66.00 53.00 88.00
1984 54.00 56.00 ----- z 72.00 87.00 91.00 96.00 86.00 85.00 74.00 64.00 52.00 96.00
1985 55.00 55.00 62.00 76.00 77.00 90.00 95.00 90.00 83.00 77.00 67.00 54.00 95.00
1986 61.00 68.00 70.00 75.00 88.00 88.00 89.00 89.00 86.00 71.00 60.00 55.00 89.00
1987 53.00 55.00 58.00 75.00 74.00 85.00 86.00 84.00 83.00 80.00 58.00 61.00 86.00
1988 53.00 58.00 67.00 75.00 79.00 89.00 89.00 86.00 83.00 80.00 68.00 60.00 89.00
1989 51.00 59.00 66.00 78.00 80.00 88.00 98.00 87.00 82.00 76.00 69.00 61.00 98.00
1990 64.00 53.00 67.00 73.00 74.00 90.00 88.00 88.00 87.00 73.00 67.00 56.00 90.00
1991 47.00 59.00 50.00 69.00 75.00 82.00 93.00 89.00 85.00 80.00 64.00 52.00 93.00
1992 56.00 56.00 59.00 80.00 77.00 84.00 88.00 91.00 79.00 74.00 59.00 49.00 91.00
1993 49.00 43.00 58.00 70.00 74.00 83.00 84.00 88.00 w 81.00 u 79.00 59.00 55.00 88.00
1994 61.00 55.00 65.00 76.00 80.00 92.00 90.00 94.00 83.00 69.00 64.00 ----- z 94.00
1995 57.00 62.00 63.00 69.00 74.00 85.00 92.00 90.00 89.00 76.00 67.00 62.00 92.00
1996 60.00 64.00 67.00 77.00 87.00 89.00 99.00 92.00 88.00 83.00 67.00 50.00 99.00
1997 49.00 55.00 72.00 72.00 85.00 84.00 93.00 87.00 80.00 76.00 69.00 52.00 93.00
1998 52.00 44.00 68.00 70.00 72.00 88.00 94.00 90.00 81.00 73.00 60.00 58.00 94.00
1999 57.00 64.00 64.00 73.00 78.00 89.00 90.00 83.00 84.00 79.00 71.00 53.00 90.00
2000 58.00 57.00 65.00 79.00 87.00 90.00 95.00 i 93.00 88.00 78.00 55.00 56.00 95.00
2001 59.00 58.00 66.00 74.00 84.00 91.00 92.00 91.00 85.00 80.00 64.00 48.00 92.00
2002 56.00 64.00 69.00 74.00 90.00 91.00 97.00 95.00 87.00 74.00 64.00 49.00 97.00
2003 62.00 55.00 65.00 67.00 89.00 91.00 96.00 93.00 88.00 82.00 58.00 56.00 96.00
2004 51.00 50.00 75.00 74.00 80.00 88.00 92.00 93.00 89.00 76.00 64.00 58.00 93.00
2005 56.00 48.00 67.00 71.00 83.00 88.00 95.00 86.00 84.00 75.00 63.00 60.00 95.00
2006 57.00 57.00 56.00 72.00 82.00 93.00 95.00 89.00 82.00 74.00 71.00 55.00 95.00
2007 52.00 57.00 75.00 78.00 81.00 93.00 97.00 91.00 90.00 73.00 71.00 56.00 97.00
2008 43.00 53.00 62.00 73.00 85.00 88.00 91.00 91.00 86.00 79.00 ----- z 63.00 91.00
2009 55.00 57.00 66.00 76.00 85.00 90.00 95.00 93.00 87.00 76.00 71.00 50.00 95.00
2010 41.00 z 48.00 62.00 69.00 75.00 90.00 96.00 89.00 88.00 84.00 74.00 57.00 96.00
2011 55.00 55.00 64.00 73.00 75.00 88.00 97.00 91.00 86.00 77.00 61.00 59.00 97.00
2012 57.00 52.00 69.00 81.00 83.00 91.00 91.00 89.00 a 90.00 80.00 70.00 57.00 91.00
2013 54.00 55.00 ----- z ----- z ----- z ----- z ----- z ----- z ----- z ----- z ----- z ----- z 55.00
Period of Record Statistics
MEAN 54.00 55.45 61.90 71.78 79.31 87.20 90.21 87.89 83.57 75.01 64.87 55.89 91.28
S.D. 5.32 5.67 5.74 4.19 4.26 3.76 3.84 3.93 3.90 4.26 4.57 4.72 3.36
SKEW -0.81 -0.25 0.03 -0.23 0.04 -0.16 0.04 -0.49 -0.30 -0.03 -0.48 0.17 0.04
MAX 64.00 68.00 76.00 81.00 90.00 95.00 99.00 95.00 91.00 84.00 74.00 67.00 99.00
MIN 35.00 41.00 48.00 60.00 67.00 79.00 81.00 77.00 73.00 64.00 52.00 47.00 85.00
NO YRS 97 98 96 97 96 97 96 97 97 98 97 95 80