Historical Climate Data

Precipitation Summary

Station: 114108 HILLSBORO, IL

1971-2000 NCDC Normals

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
Prec. (in) 2.18 2.00 3.56 4.19 4.31 4.07 3.48 3.53 3.16 2.91 3.81 2.98 40.18

Precipitation Extremes

Period of Record: 1895-2006


Month
High (in)
Year
Low (in)
Year 		1-Day
Max (in)
Date
Jan 8.74 1950 0.02 1986 2.47 01-03-1950
Feb 6.31 1951 0.09 1947 2.28 02-10-1959
Mar 9.26 1938 0.00 1910 3.19 03-14-1922
Apr 10.95 1994 0.55 1895 4.67 04-29-1996
May 13.42 1990 0.13 1914 4.02 05-25-1990
Jun 12.09 1957 0.18 1933 4.08 06-28-1951
Jul 10.98 1958 0.34 1919 4.07 07-15-1955
Aug 13.12 1915 0.40 1943 5.49 08-21-1915
Sep 9.07 1926 0.00 1897 4.97 09-17-1969
Oct 9.72 1905 0.10 1908 6.53 10-18-1905
Nov 9.56 1985 0.09 1904 3.45 11-18-2003
Dec 8.71 1971 0.05 1958 3.72 12-08-1966
             
Annual 62.39 1982 25.59 1914 6.53 10-18-1905
Winter 18.65 1950 2.63 1931 3.72 12-08-1966
Spring 25.20 2002 3.60 1914 4.67 04-29-1996
Summer 25.39 1915 3.48 1933 5.49 08-21-1915
Fall 16.93 1926 3.24 1939 6.53 10-18-1905

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 6.9 4.7 1.6 0.4
Feb 6.5 4.6 1.4 0.4
Mar 9.3 7.3 2.7 0.7
Apr 9.6 7.2 3.0 1.0
May 10.1 7.3 3.1 1.1
Jun 8.3 6.6 2.9 1.0
Jul 8.0 6.2 2.6 0.8
Aug 7.6 5.7 2.4 1.0
Sep 6.9 5.3 2.3 0.9
Oct 7.7 5.1 2.0 0.9
Nov 8.1 6.8 2.8 1.2
Dec 7.7 5.3 2.1 0.8
         
Annual 96.7 72.2 29.0 10.2
Winter 21.1 14.6 5.1 1.7
Spring 28.9 21.8 8.8 2.8
Summer 24.0 18.6 8.0 2.7
Fall 22.7 17.2 7.1 2.9

Temperature Summary

Station 114108 HILLSBORO, IL

1971-2000 NCDC Normals

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
High °F 37.4 44.1 55.7 68.1 78.0 87.0 90.7 89.0 82.2 70.7 54.8 41.7 66.6
Low °F 21.1 25.9 35.3 45.2 55.0 64.2 68.0 65.6 57.6 46.7 37.0 26.1 45.6
Mean °F 29.3 35.0 45.5 56.7 66.5 75.6 79.4 77.3 69.9 58.7 45.9 33.9 56.1
HDD 1107 840 605 271 99 4 0 2 36 225 574 964 4727
CDD 0 0 0 20 146 322 445 383 182 29 0 0 1527

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

Temperature Extremes

Period of Record: 1895-2006


Month 		High
Mean °F
Year 		Low
Mean °F
Year 		1-Day
Max °F
Date 		1-Day
Min °F
Date
Jan 42.1 2006 13.9 1977 75 01-23-1909 -21 01-12-1918
Feb 43.3 1930 20.4 1899 79 02-24-1930 -22 02-14-1905
Mar 55.7 1946 28.6 1960 90 03-24-1929 -10 03-06-1960
Apr 62.2 2006 44.4 1907 92 04-26-1989 18 04-05-1920
May 73.4 1987 57.1 1907 99 05-31-1895 28 05-25-1925
Jun 79.6 1934 66.8 1903 106 06-30-1931 37 06-16-1917
Jul 84.2 1936 72.6 1950 114 07-14-1954 45 07-15-1930
Aug 83.2 1936 68.3 1915 112 08-04-1918 39 08-29-1986
Sep 76.5 1925 61.1 1974 105 09-04-1954 26 09-30-1899
Oct 66.1 1963 47.9 1917 95 10-03-1922 17 10-29-1925
Nov 55.0 1909 36.6 1951 83 11-08-1931 -5 11-25-1950
Dec 42.6 1923 19.8 1983 74 12-03-1970 -20 12-22-1989
                 
Annual 58.0 1998 51.4 1917 114 07-14-1954 -22 02-14-1905
Winter 40.3 1932 23.3 1918 79 02-24-1930 -22 02-14-1905
Spring 59.9 1977 48.3 1960 99 05-31-1995 -10 03-06-1960
Summer 80.3 1936 70.5 1915 114 07-14-1954 37 06-16-1917
Fall 62.7 1931 51.6 1976 105 09-04-1954 -5 11-25-1950

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 11.2 27.2 2.6
Feb 0.0 6.3 21.1 1.4
Mar 0.0 1.0 14.7 0.1
Apr 0.2 0.0 3.8 0.0
May 1.3 0.0 0.1 0.0
Jun 9.6 0.0 0.0 0.0
Jul 15.7 0.0 0.0 0.0
Aug 10.7 0.0 0.0 0.0
Sep 4.3 0.0 0.1 0.0
Oct 0.1 0.0 3.4 0.0
Nov 0.0 0.8 13.3 0.0
Dec 0.0 6.3 24.3 1.6
         
Annual 41.5 25.8 108.4 5.8
Winter 0.0 23.8 72.5 5.7
Spring 1.5 1.0 18.7 0.1
Summer 35.8 0.0 0.0 0.0
Fall 4.3 0.8 17.0 0.0

Snowfall Summary

Station: 114108 HILLSBORO, IL

1971-2000 Averages

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
Snow (in) 6.3 4.0 3.1 0.5 0.0 0.0 0.0 0.0 0.0 0.0 1.0 4.5 19.4

Snowfall Extremes

Period of Record: 1895-2006

Month High (in) Year 1-Day Max (in) Date
Jan 24.3 1987 11.0 01-31-1982
Feb 22.0 1910 14.0 02-21-1912
Mar 26.5 1978 14.0 03-19-1906
Apr 7.0 1971 7.0 04-06-1971
May 5.0 1929 5.0 05-02-1929
Jun 0.0 - - -
Jul 0.0 - - -
Aug 0.0 - - -
Sep 0.0 - - -
Oct 1.8 1929 1.8 10-23-1929
Nov 10.9 1951 10.4 11-06-1951
Dec 25.5 1973 11.0 12-31-1973
Season (Jul-Jun) 58.0 1911-1912 14.0 03-19-1906

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 1.7 1.2 0.7 0.3
Feb 1.7 1.2 0.7 0.3
Mar 1.2 1.0 0.5 0.2
Apr 0.2 0.2 0.1 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 0.6 0.4 0.2 0.1
Dec 1.9 1.5 0.9 0.3
Annual 7.9 5.9 3.5 1.2

Growing Season Summary

Station: 114108 HILLSBORO, 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 25 67 218 472 788 1027 1182 1099 851 541 207 51 6451
45 9 31 130 337 633 878 1027 946 702 393 125 23 5171
50 2 11 71 218 480 728 872 792 554 261 67 9 4017
55 0 3 33 126 333 579 717 639 410 153 30 3 2989
60 0 0 13 60 205 430 562 486 275 74 11 0 2090
50** 14 42 135 289 503 690 803 745 558 338 119 28 4214

**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 4/10 3/26 4/01 4/29 5/04 10/17 9/20 9/28 11/01 11/10
30 4/07 3/20 3/25 4/22 5/04 10/22 9/22 10/04 11/13 11/21
28 4/07 3/18 3/21 4/17 4/23 11/03 10/02 10/09 11/21 11/29
24 3/24 3/02 3/13 4/09 4/11 11/10 10/13 10/24 11/30 12/04
20 3/15 2/19 2/27 3/27 4/06 11/21 10/24 11/05 12/08 12/25
16 3/02 1/16 2/01 3/23 3/27 12/02 11/02 11/11 12/22 12/25

Length of Growing Season (Days)

Derived from 1971-2000 Averages

Temp °F Median Shortest 10% 90% Longest
32 185 156 166 201 215
30 200 156 176 223 228
28 209 176 186 239 252
24 229 191 209 257 268
20 252 221 229 281 287
16 279 228 247 316 339

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