Historical Climate Data

Precipitation Summary

Station: 110072 ALEDO, IL

1971-2000 NCDC Normals

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
Prec. (in) 1.27 1.29 2.43 3.69 3.92 4.43 4.21 4.28 3.31 2.73 2.50 1.92 35.98

Precipitation Extremes

Period of Record: 1900-2006


Month
High (in)
Year
Low (in)
Year 		1-Day
Max (in)
Date
Jan 4.71 1916 0.07 1981 2.23 01-24-1938
Feb 4.00 2001 0.11 1947 1.75 02-21-1997
Mar 6.64 1991 0.10 1918 2.90 03-24-1954
Apr 9.99 1973 0.72 1915 4.87 04-21-1973
May 11.60 2001 0.45 1992 4.80 05-01-2003
Jun 11.97 1993 0.07 1963 3.74 06-26-1973
Jul 12.51 1982 0.10 1913 4.06 07-18-1902
Aug 11.96 1977 0.24 1947 6.90 08-17-1930
Sep 13.44 1911 0.00 1979 5.22 09-13-1961
Oct 10.10 1941 0.00 1964 5.17 10-06-1955
Nov 6.22 1934 0.06 1917 2.58 11-06-1944
Dec 5.75 1987 0.23 1919 2.70 12-15-1987
             
Annual 55.92 1993 19.33 1901 6.90 08-17-1930
Winter 8.83 1988 0.88 1920 2.70 12-15-1987
Spring 21.49 1973 3.71 1936 4.87 04-21-1973
Summer 32.41 1993 3.61 1991 6.90 08-17-1930
Fall 20.00 1911 2.69 1950 5.22 09-13-1961

Precipitation Threshold Climatology

Derived from 1971-2000 Averages:

*Annual/seasonal totals may differ from the sum of the monthly totals due to rounding.


Month 		# Days
Total ≥ 0.01" 		# Days
Total ≥ 0.10" 		# Days
Total ≥ 0.50" 		# Days
Total ≥ 1.00"
Jan 6.3 3.4 0.7 0.2
Feb 5.4 3.5 0.7 0.1
Mar 8.2 5.8 1.7 0.6
Apr 9.3 6.9 2.5 1.0
May 9.8 7.7 2.6 1.0
Jun 8.5 6.8 2.9 1.4
Jul 8.2 6.6 2.8 1.2
Aug 8.1 6.5 2.6 1.2
Sep 6.8 5.5 2.2 0.8
Oct 7.0 5.3 1.9 0.6
Nov 7.3 5.5 1.6 0.4
Dec 6.1 4.2 1.0 0.4
         
Annual 91.2 67.6 23.1 8.8
Winter 17.9 11.1 2.4 0.7
Spring 27.4 20.3 6.9 2.5
Summer 24.8 20.0 8.3 3.8
Fall 21.1 16.3 5.6 1.8

Temperature Summary

Station 110072 ALEDO, IL

1971-2000 NCDC Normals

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
High °F 28.9 34.6 47.3 60.9 71.6 80.8 84.4 82.2 75.2 63.5 46.7 33.5 59.1
Low °F 11.1 16.4 26.4 37.0 48.5 58.8 62.3 59.9 51.4 39.6 28.0 17.0 38.0
Mean °F 20.0 25.5 36.9 49.0 60.1 69.8 73.4 71.1 63.3 51.6 37.4 25.3 48.6
HDD 1395 1107 873 485 206 24 5 28 117 422 830 1232 6724
CDD 0 0 0 3 53 169 263 217 65 4 0 0 774

HDD - heating degree days (base 65F); CDD - cooling degree days (base 65F)

Temperature Extremes

Period of Record: 1900-2006


Month 		High
Mean °F
Year 		Low
Mean °F
Year 		1-Day
Max °F
Date 		1-Day
Min °F
Date
Jan 35.5 1933 9.1 1977 69 01-31-1989 -25 01-19-1994
Feb 37.9 1954 13.1 1936 72 02-15-1921 -30 02-13-1905
Mar 50.1 1910 23.2 1960 94 03-22-1928 -15 03-01-1962
Apr 58.6 1915 44.2 1920 93 04-10-1930 10 04-06-1982
May 69.6 1934 54.4 1997 103 05-31-1934 23 05-04-2005
Jun 79.4 1934 65.4 1916 104 06-29-1936 36 06-04-1945
Jul 85.4 1936 70.5 1924 113 07-15-1936 44 07-14-1975
Aug 81.8 1947 65.5 2004 106 08-18-1936 38 08-30-1915
Sep 72.8 1933 58.5 1975 102 09-06-1922 24 09-28-1942
Oct 65.3 1963 42.8 1925 92 10-02-1953 9 10-28-1925
Nov 47.8 1931 31.1 1996 81 11-01-1902 -6 11-26-1977
Dec 36.2 1923 12.1 2000 70 12-05-1998 -22 12-28-1924
                 
Annual 54.5 1931 45.5 1986 113 07-15-1936 -30 02-13-1905
Winter 33.7 1932 17.1 1936 72 02-15-1921 -30 02-13-1905
Spring 56.9 1977 44.2 1996 103 05-31-1934 -15 03-01-1962
Summer 79.8 1936 68.0 2004 113 07-15-1936 36 06-04-1945
Fall 59.6 1931 48.1 1995 102 09-06-1922 -6 11-26-1977

Temperature Threshold Climatology

Derived from 1971-2000 Averages:

*Annual/seasonal values may differ from the sum of the monthly values due to rounding.


Month 		# Days
High ≥ 90°F 		# Days
High ≤ 32°F 		# Days
Low ≤ 32°F 		# Days
Low ≤ 0°F
Jan 0.0 16.8 29.5 6.8
Feb 0.0 11.1 24.5 3.2
Mar 0.0 3.3 19.8 0.2
Apr 0.1 0.1 6.7 0.0
May 0.8 0.0 0.2 0.0
Jun 4.1 0.0 0.0 0.0
Jul 8.6 0.0 0.0 0.0
Aug 5.5 0.0 0.0 0.0
Sep 1.9 0.0 0.4 0.0
Oct 0.1 0.0 4.9 0.0
Nov 0.0 2.7 17.9 0.1
Dec 0.0 11.9 28.0 3.5
         
Annual 20.6 46.5 135.6 14.3
Winter 0.0 39.9 82.1 13.5
Spring 0.9 3.4 27.1 0.2
Summer 18.1 0.0 0.0 0.0
Fall 1.9 2.8 23.6 0.1

Snowfall Summary

Station: 110072 ALEDO, IL

1971-2000 Averages

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
Snow (in) 8.7 6.1 3.8 1.0 0.0 0.0 0.0 0.0 0.0 0.2 2.2 6.8 28.8

Snowfall Extremes

Period of Record: 1900-2006

Month High (in) Year 1-Day Max (in) Date
Jan 26.9 1979 18.0 01-14-1979
Feb 19.2 1975 9.0 02-24-1975
Mar 18.0 1972 11.0 03-29-1972
Apr 11.0 1982 9.0 04-17-1912
May 0.0 - - -
Jun 0.0 - - -
Jul 0.0 - - -
Aug 0.0 - - -
Sep 0.0 - - -
Oct 5.0 1967 5.0 10-27-1967
Nov 12.0 1974 6.1 11-18-1926
Dec 31.0 2000 10.0 12-12-2000
Season (Jul-Jun) 57.0 1978-1979 18.0 01-14-1979

Snowfall Threshold Climatology

Derived from 1971-2000 Averages

*Annual values may differ from the sum of the monthly values due to rounding.


Month 		# Days
Total ≥ 0.1" 		# Days
Total ≥ 1.0" 		# Days
Total ≥ 2.0" 		# Days
Total ≥ 5.0"
Jan 3.2 2.1 1.2 0.3
Feb 3.2 2.1 1.2 0.3
Mar 1.9 1.3 0.9 0.1
Apr 0.5 0.3 0.2 0.1
May 0.0 0.0 0.0 0.0
Jun 0.0 0.0 0.0 0.0
Jul 0.0 0.0 0.0 0.0
Aug 0.0 0.0 0.0 0.0
Sep 0.0 0.0 0.0 0.0
Oct 0.1 0.1 0.0 0.0
Nov 1.2 0.8 0.6 0.1
Dec 3.3 2.4 1.4 0.3
Annual 14.6 9.6 5.7 1.2

Growing Season Summary

Station: 110072 ALEDO, IL

Growing Degree Day Averages

Derived from 1971-2000 Data

Base Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
40 5 21 120 353 682 928 1075 1018 741 426 113 15 5343
45 1 6 66 233 528 779 920 864 592 291 57 6 4218
50 0 1 34 137 379 631 766 709 445 178 25 2 3210
55 0 0 14 70 244 483 612 555 307 95 8 0 2317
60 0 0 5 32 136 338 457 400 189 40 1 0 1553
50** 3 13 78 218 419 618 731 686 470 255 62 8 3460

**Modified Growing Degree Days: Base 50, Ceiling 86.

Growing Season Summary

Derived from 1971-2000 Averages

Date of Last Spring Occurrence Date of First Fall Occurrence
Temp °F Median Early 90% 10% Late Median Early 90% 10% Late
32 4/21 3/29 4/06 5/06 5/17 10/09 9/22 9/23 11/02 11/05
30 4/15 3/25 3/31 4/26 5/04 10/17 9/22 9/27 11/04 11/10
28 4/11 3/25 3/31 4/21 4/29 10/20 10/02 10/04 11/05 11/11
24 4/05 2/21 3/14 4/14 4/19 11/03 10/02 10/19 11/18 11/25
20 3/21 2/21 3/04 4/07 4/10 11/14 10/20 11/01 11/29 12/11
16 3/13 2/09 2/18 3/27 4/07 11/21 11/03 11/07 12/09 12/22

Length of Growing Season (Days)

Derived from 1971-2000 Averages

Temp °F Median Shortest 10% 90% Longest
32 176 140 153 201 203
30 185 151 160 207 225
28 195 173 176 211 225
24 216 190 193 241 268
20 240 194 215 262 283
16 258 220 231 284 286

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Copyright 2007 Illinois State Water Survey
Jim Angel, State Climatologist, jimangel@illinois.edu
Last Modified: September 11, 2007