A Comparison Study Examining 90º and Higher Daily Temperatures for the days Up To and Including July 31st of 2008 and then comparing the Same 90º and Higher Daily Temperatures for the period of August 1st and Beyond for each respective year (1871-2007) of Chicago's Official Climate Stations.
So far, up to and including the date of July 31st in this 2008 Calendar Year Chicago has Officially experienced 3 Days of 90º or Higher Temperatures: June 12 91º July 15 90º July 16 90º
Examination # 1
Using a Range of 5 Day Increments
0 - 5 90º Days thru 7/31 occurred in 40 past years produced an Average of 3 Additional 90ºs after August 1
6 -10 90º Days thru 7/31 occurring in 39 past years produced an Average of 6 Additional 90ºs after August 1
11-15 90º Days thru 7/31 occurring in 30 past years produced an Average of 5 Additional 90ºs after August 1
16-20 90º Days thru 7/31 occurring in 14 past years produced an Average of 10 Additional 90ºs after August 1
21-25 90º Days thru 7/31 occurring in 7 past years produced an Average of 12 Additional 90ºs after August 1
26-30 90º Days thru 7/31 occurring in 6 past years produced an Average of 7 Additional 90ºs after August 1
32 90º Days thru 7/31 occurring in 1 past year produced an Average of 15 Additional 90ºs after August 1
Examination # 2
A Summary of the number of Days which reached 90º & Higher up to July 31st.
The number of times (years) this had occurred in the past 137 years (1871 - 2007).
The percentage of times this occurred.
# of 90º+ Days Totals Years This Percentage
Up to July 31st has Occurred of Times
32 1
½%
29 1
½%
28 1
½%
27 3
2%
26 1
½%
23 4
3%
21 3
2%
19 4
3%
18 1
½%
17 6
4%
16 3
2%
15 6
4%
14 4
3%
13 7
9%
12 3
2%
11 10
7%
10 3
2%
9 6
4%
8 4
3%
7 13
9%
6 13
9%
5 10
7%
4 9
7%
3 9
7% <-- 2008
2 4
3%
1 3
2%
0 5 3½%
Totals 137 100%
Examintation # 3
There are Two separate columns below. Each list the following:
1) The number of Days reaching 90º & Higher for each year up to July 31st.
2) The Exact Calendar Year for that respective line.
3) The number of Days reaching 90º & Higher for each year beginning with August 1st & after.
4) The Total number of 90º & Higher Days for that respective year.
# of 90º Days # of 90º Days Total 90º Days # of 90º Days # of 90º Days Total 90º Days
Up to July 31st Year From 8-1 After For that Year Up to July 31st Year From 8-1 After For that Year
32 1988 15 47 8 1951 3 11
29 1977 4 33 8 1984 12 20
28 1954 8 36 7 1887 4 11
27 1934 5 32 7 1890 2 9
27 1952 11 38 7 1892 2 9
27 1987 6 33 7 1898 7 14
26 1964 9 35 7 1900 11 18
23 1949 7 30 7 1922 9 16
23 1953 19 42 7 1927 4 11
23 1955 23 46 7 1937 8 15
23 1983 19 42 7 1961 9 16
21 1911 4 25 7 1965 3 10
21 1921 2 23 7 1982 1 8
21 1944 13 44 7 1985 5 12
19 1943 8 27 7 1989 1 8
19 1966 1 20 6 1876 1 7
19 1991 11 30 6 1879 1 7
18 2002 5 23 6 1893 3 9
17 1933 4 21 6 1897 6 12
17 1959 22 39 6 1905 3 9
17 1970 9 26 6 1906 4 10
17 1971 18 35 6 1918 8 14
17 1975 9 26 6 1929 3 9
17 1999 5 22 6 1935 6 12
16 1931 15 31 6 1947 23 29
16 1962 10 26 6 1981 0 6
16 2005 10 26 6 1993 5 11
15 1901 1 16 6 1996 4 10
15 1913 7 22 5 1880 1 6
15 1946 6 21 5 1881 7 12
15 1956 6 21 5 1888 0 5
15 1963 6 21 5 1896 6 11
15 1980 12 27 5 1908 8 13
14 1930 4 18 5 1917 1 6
14 1969 3 17 5 1960 12 17
14 1972 3 17 5 1978 8 13
14 1994 3 17 5 1990 5 10
13 1923 0 13 5 2003 5 10
13 1942 4 17 4 1873 3 7
13 1968 11 24 4 1883 0 4
13 1973 16 29 4 1885 0 4
13 1976 3 16 4 1924 5 5
13 2001 5 18 4 1926 2 6
13 2006 2 15 4 1938 5 9
12 1914 4 16 4 1958 7 11
12 1925 7 19 4 1967 0 4
12 1957 7 19 4 1992 2 6
11 1874 6 17 3 1878 1 4
11 1894 4 15 3 1886 1 4
11 1936 9 20 3 1899 5 8
11 1940 3 14 3 1902 0 3
11 1941 7 18 3 1904 1 4
11 1950 2 13 3 1909 2 5
11 1974 2 13 3 1912 9 12
11 1986 2 13 3 1928 4 7
11 1998 4 15 3 1939 9 12
11 2007 8 19 2 1877 0 2
10 1872 8 18 2 1889 0 2
10 1932 6 16 2 1907 2 4
10 1997 3 13 2 2004 1 3
9 1895 9 18 1 1871 1 2
9 1910 0 9 1 1882 0 1
9 1916 8 17 1 1979 1 2
9 1919 8 17 0 1875 0 0
9 1920 3 12 0 1884 1 1
9 1948 10 19 0 1891 5 5
8 1903 2 10 0 1915 1 1
8 1945 8 16 0 2000 4 4
A more specific examination of Meteorological Summer of 2008 for the months of June and July with attention to Daily Maximum Temperatures and Daily Rainfall.
June 2008 Maximum Temperatures
10 Days Below the Average Daily Maximum Temperature
20 Days Above the Average Daily Maximum Temperature
June 2008 Average High Temperature: 80.9º
June 30 Year Normal High Temperature: 79.2º
June 2008 Monthly High Temperatures were
1.7º Above Normal
June 2008 Daily Rainfall
13 Days Experienced Measurable Rainfall of 0.01" or Greater
17 Days Did Not Experience Measurable Rainfall of 0.01" or Greater
June 2008 Monthly Rainfall: 4.18"
June 30 Year Normal Monthly Rainfall: 3.63"
June 2008 Monthly Rainfall was
0.55" Above Normal
July 2008 Maximum Temperatures
12 Days Below the Average Daily Maximum Temperature
18 Days Above the Average Daily Maximum Temperature
1 Day Equalled the Average Daily Maximum Temperature
July 2008 Average High Temperature: 83.8º
July 30 Year Normal High Temperature: 83.5º
July 2008 Monthly High Temperatures were
0.3º Above Normal
July 2008 Daily Rainfall
12 Days Experienced Measurable Rainfall of 0.01" or Greater
19 Days Did Not Experience Measurable Rainfall of 0.01" or Greater
July 2008 Monthly Rainfall: 4.76"
July 30 Year Normal Monthly Rainfall: 3.51"
July 2008 Monhly Rainfall was:
1.25" Above Normal
