Historical Climate Data

Precipitation Summary

Station: 111436 CHARLESTON, IL

1971-2000 NCDC Normals

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
Prec. (in) 2.20 2.40 3.35 3.98 4.23 3.94 4.65 3.46 3.17 3.25 3.87 3.23 41.73

Precipitation Extremes

Period of Record: 1896-2006


Month
High (in)
Year
Low (in)
Year 		1-Day
Max (in)
Date
Jan 9.78 1950 0.00 1986 2.65 01-18-1949
Feb 5.46 1990 0.10 1947 2.70 02-27-1997
Mar 10.63 1945 0.40 1910 4.16 03-14-1922
Apr 8.63 1922 0.22 1971 3.55 04-07-2006
May 11.59 2002 0.52 1911 4.66 05-07-2002
Jun 13.98 1957 0.66 1936 6.50 06-28-1957
Jul 10.10 1987 0.29 1947 5.18 07-21-1973
Aug 10.41 1981 0.33 1929 4.49 08-29-1951
Sep 14.14 1926 0.12 1979 6.00 09-09-1926
Oct 9.33 2001 0.18 1908 3.61 10-07-1982
Nov 11.57 1985 0.18 1904 2.75 11-17-1958
Dec 8.33 1990 0.00 1955 2.87 12-30-1990
             
Annual 56.60 2000 25.40 1914 6.50 06-28-1957
Winter 18.39 1950 1.52 1963 2.87 12-30-1990
Spring 23.38 2002 4.35 1914 4.66 05-07-2002
Summer 24.26 2000 2.79 1984 6.50 06-28-1957
Fall 21.23 1926 3.56 1953 6.00 09-09-1926

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 9.2 5.4 1.3 0.3
Feb 8.7 5.5 1.5 0.5
Mar 10.6 7.3 2.5 0.5
Apr 11.6 8.5 2.9 0.8
May 10.2 7.4 2.8 1.1
Jun 9.0 6.6 2.7 1.0
Jul 8.9 6.5 3.3 1.4
Aug 7.8 5.5 2.3 1.1
Sep 7.0 4.9 2.4 0.9
Oct 7.8 5.3 2.1 0.9
Nov 10.2 6.8 2.8 1.1
Dec 9.9 6.7 2.2 0.9
         
Annual 110.7 76.4 29.0 10.6
Winter 27.8 17.7 5.0 1.7
Spring 32.4 23.2 8.2 2.5
Summer 25.7 18.6 8.4 3.5
Fall 24.9 16.9 7.3 2.9

Temperature Summary

Station 111436 CHARLESTON, IL

1971-2000 NCDC Normals

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
High °F 35.2 41.0 52.7 65.0 75.5 84.5 87.8 85.6 79.3 67.6 52.5 39.9 63.9
Low °F 18.6 23.5 32.8 42.5 52.3 61.0 65.0 63.3 55.9 44.9 34.4 23.7 43.2
Mean °F 26.9 32.3 42.8 53.8 63.9 72.8 76.4 74.5 67.6 56.3 43.5 31.8 53.6
HDD 1182 918 690 345 134 8 0 7 57 294 646 1029 5310
CDD 0 0 0 7 100 241 354 300 135 22 0 0 1159

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

Temperature Extremes

Period of Record: 1896-2006


Month 		High
Mean °F
Year 		Low
Mean °F
Year 		1-Day
Max °F
Date 		1-Day
Min °F
Date
Jan 40.7 2006 12.7 1977 71 01-23-1909 -27 01-19-1994
Feb 42.0 1930 19.2 1978 75 02-24-1930 -23 02-13-1905
Mar 54.6 1946 24.1 1960 89 03-24-1929 -14 03-06-1960
Apr 60.9 1896 43.9 1907 92 04-11-1930 17 04-07-1982
May 71.7 1962 56.6 1917 101 05-31-1934 26 05-25-1925
Jun 80.8 1934 66.6 1928 108 06-28-1934 35 06-04-1945
Jul 84.7 1936 72.2 1915 110 07-14-1936 45 07-01-1937
Aug 82.2 1947 67.5 1915 107 08-05-1918 39 08-31-1915
Sep 75.4 1933 59.8 1918 104 09-06-1925 25 09-30-1899
Oct 66.1 1963 47.2 1925 96 10-21-1912 11 10-29-1925
Nov 52.7 1931 35.7 1976 84 11-01-1933 -2 11-30-1929
Dec 42.3 1923 19.2 2000 73 12-15-1948 -20 12-28-1924
                 
Annual 57.3 1921 50.6 1917 110 07-14-1936 -27 01-19-1994
Winter 40.1 1932 21.8 1978 75 02-24-1930 -27 01-19-1994
Spring 59.0 1977 47.1 1960 101 05-31-1934 -14 03-06-1960
Summer 80.0 1936 69.5 1915 110 07-14-1936 35 06-04-1945
Fall 62.2 1931 49.5 1952 104 09-06-1925 -2 11-30-1929

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 12.8 26.6 3.4
Feb 0.0 7.5 21.3 1.8
Mar 0.0 1.6 15.4 0.1
Apr 0.0 0.0 4.5 0.0
May 0.4 0.0 0.2 0.0
Jun 5.1 0.0 0.0 0.0
Jul 8.4 0.0 0.0 0.0
Aug 5.9 0.0 0.0 0.0
Sep 2.0 0.0 0.1 0.0
Oct 0.0 0.0 3.2 0.0
Nov 0.0 0.8 12.8 0.0
Dec 0.0 7.0 23.8 1.5
         
Annual 21.9 29.7 107.6 6.8
Winter 0.0 27.3 71.6 6.7
Spring 0.4 1.6 20.3 0.1
Summer 19.4 0.0 0.0 0.0
Fall 2.0 0.8 16.0 0.0

Snowfall Summary

Station: 111436 CHARLESTON, IL

1971-2000 Averages

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
Snow (in) 9.4 4.1 2.8 0.2 0.0 0.0 0.0 0.0 0.0 0.0 1.5 4.9 22.9

Snowfall Extremes

Period of Record: 1896-2006

Month High (in) Year 1-Day Max (in) Date
Jan 32.1 1996 12.0 01-30-1982
Feb 24.0 1908 10.0 02-15-1908
Mar 16.0 1978 7.4 03-10-1964
Apr 4.0 1957 4.0 04-09-1957
May 0.0 - - -
Jun 0.0 - - -
Jul 0.0 - - -
Aug 0.0 - - -
Sep 0.0 - - -
Oct 1.0 1913 1.0 10-29-1913
Nov 10.6 1975 8.1 11-06-1951
Dec 17.4 1950 8.3 12-26-1975
Season (Jul-Jun) 47.6 1995-1996 12.0 01-30-1982

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 3.0 1.6 0.8 0.1
Feb 3.0 1.6 0.8 0.1
Mar 1.4 0.9 0.6 0.2
Apr 0.3 0.1 0.0 0.0
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 0.0 0.0 0.0 0.0
Nov 0.8 0.5 0.3 0.1
Dec 3.1 1.7 1.2 0.2
Annual 13.7 8.1 4.7 1.0

Growing Season Summary

Station: 111436 CHARLESTON, 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 24 54 190 433 740 987 1131 1069 830 510 187 43 6204
45 9 24 111 300 588 837 976 914 680 366 110 19 4939
50 3 8 59 187 438 687 821 759 532 238 57 8 3802
55 0 2 28 103 296 538 666 604 387 138 24 2 2794
60 0 0 9 47 174 389 511 450 255 65 7 0 1912
50** 11 29 111 257 466 670 784 736 543 305 100 21 4038

**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 4/18 3/28 4/06 5/05 5/12 10/18 9/19 10/04 11/03 11/03
30 4/11 3/27 4/03 4/25 5/12 10/23 10/02 10/08 11/05 11/20
28 4/08 3/18 3/24 4/13 4/19 11/02 10/03 10/12 11/13 11/22
24 3/25 2/22 3/13 4/10 4/19 11/12 10/23 11/01 12/05 12/11
20 3/18 2/22 3/07 4/07 4/18 11/20 10/24 11/04 12/08 12/21
16 3/08 2/08 2/12 3/19 3/25 12/04 11/02 11/13 12/22 12/26

Length of Growing Season (Days)

Derived from 1971-2000 Averages

Temp °F Median Shortest 10% 90% Longest
32 183 151 162 205 212
30 195 163 167 211 225
28 208 177 186 231 235
24 228 206 212 254 261
20 243 220 224 267 283
16 274 237 248 299 311

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