Historical Climate Data

Precipitation Summary

Station: 115768 MONMOUTH, IL

1971-2000 NCDC Normals

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
Prec. (in) 1.62 1.72 2.85 3.76 4.27 4.26 4.33 4.02 3.45 2.97 2.74 2.32 38.31

Precipitation Extremes

Period of Record: 1893-2006


Month
High (in)
Year
Low (in)
Year 		1-Day
Max (in)
Date
Jan 5.74 1965 0.04 1919 2.30 01-24-1938
Feb 4.32 1997 0.14 1917 2.85 02-21-1997
Mar 5.51 1945 0.26 1958 2.65 03-19-1948
Apr 8.24 1950 0.98 1962 3.11 04-24-1950
May 11.29 1908 0.86 1964 2.83 05-04-1990
Jun 13.97 1902 0.82 1900 5.76 06-12-1946
Jul 12.57 1982 0.05 1913 6.53 07-15-1929
Aug 9.97 1965 0.37 1901 4.90 08-16-1898
Sep 20.03 1911 0.03 1979 4.48 09-24-1911
Oct 14.75 1941 0.05 1964 4.14 10-01-1927
Nov 7.36 1934 0.02 1917 2.46 11-27-1990
Dec 4.81 1895 0.11 1893 3.75 12-10-2003
             
Annual 54.52 1998 21.96 1910 6.53 07-15-1929
Winter 8.70 1949 0.88 1920 3.75 12-10-2003
Spring 16.98 1945 4.41 1901 3.11 04-24-1950
Summer 30.28 1902 3.85 1913 6.53 07-15-1929
Fall 25.41 1911 2.81 2002 4.48 09-24-1911

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 7.7 4.6 0.7 0.2
Feb 7.0 4.5 1.0 0.2
Mar 9.5 6.7 1.8 0.5
Apr 10.6 7.0 2.6 1.0
May 11.7 8.1 3.2 0.9
Jun 9.6 6.7 2.9 1.3
Jul 8.8 6.2 2.7 1.3
Aug 8.6 5.9 2.6 1.0
Sep 8.0 5.7 2.4 0.8
Oct 8.7 5.9 1.7 0.6
Nov 8.8 5.9 2.0 0.4
Dec 8.2 5.1 1.3 0.6
         
Annual 107.3 72.3 24.8 8.9
Winter 22.8 14.2 3.0 1.0
Spring 31.8 21.9 7.5 2.4
Summer 27.1 18.8 8.2 3.6
Fall 25.6 17.4 6.0 1.8

Temperature Summary

Station 115768 MONMOUTH, IL

1971-2000 NCDC Normals

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
High °F 30.6 36.9 49.4 62.7 72.9 81.3 84.8 83.3 77.4 65.4 49.1 35.1 60.7
Low °F 14.8 20.4 30.3 40.5 50.8 60.1 64.1 61.8 53.9 43.3 31.5 20.2 41.0
Mean °F 22.7 28.7 39.9 51.6 61.9 70.7 74.5 72.6 65.7 54.4 40.3 27.7 50.9
HDD 1312 1018 780 407 170 19 3 16 80 341 740 1159 6045
CDD 0 0 0 6 73 190 297 249 98 10 0 0 923

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

Temperature Extremes

Period of Record: 1893-2006


Month 		High
Mean °F
Year 		Low
Mean °F
Year 		1-Day
Max °F
Date 		1-Day
Min °F
Date
Jan 37.0 2006 10.3 1977 69 01-31-1989 -25 01-20-1985
Feb 38.7 1954 13.6 1936 73 02-15-1921 -27 02-13-1905
Mar 51.5 1910 24.3 1960 88 03-21-1907 -12 03-01-1962
Apr 58.9 1955 44.3 1950 93 04-10-1930 10 04-02-1899
May 69.6 1991 55.7 1935 102 05-31-1934 25 05-14-1895
Jun 79.0 1934 64.7 1903 104 06-01-1934 33 06-06-1894
Jul 84.2 1936 70.0 1950 110 07-15-1936 43 07-22-1894
Aug 80.4 1947 67.3 1915 105 08-14-1909 38 08-31-1915
Sep 72.3 1933 59.8 1902 103 09-05-1894 18 09-30-1899
Oct 64.7 1963 43.0 1925 93 10-01-1897 7 10-30-1925
Nov 50.8 2001 33.0 1911 82 11-01-1933 -4 11-26-1898
Dec 37.6 1923 13.6 2000 69 12-03-1970 -22 12-28-1924
                 
Annual 54.8 1921 47.6 1917 110 07-15-1936 -27 02-13-1905
Winter 34.0 1932 17.4 1936 73 02-15-1921 -27 02-13-1905
Spring 57.3 1977 46.2 1960 102 05-31-1934 -12 03-01-1962
Summer 79.0 1936 68.9 1915 110 07-15-1936 33 06-06-1994
Fall 58.9 1931 48.4 1976 103 09-05-1994 -4 11-26-1998

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 15.4 28.8 5.8
Feb 0.0 9.9 23.7 2.9
Mar 0.0 2.4 18.5 0.1
Apr 0.1 0.1 5.9 0.0
May 1.0 0.0 0.2 0.0
Jun 5.0 0.0 0.0 0.0
Jul 9.9 0.0 0.0 0.0
Aug 6.3 0.0 0.0 0.0
Sep 2.1 0.0 0.3 0.0
Oct 0.1 0.0 4.2 0.0
Nov 0.0 1.8 17.0 0.1
Dec 0.0 10.3 27.1 3.0
         
Annual 24.6 39.9 125.5 11.9
Winter 0.0 35.6 79.6 11.7
Spring 1.1 2.5 24.5 0.1
Summer 21.3 0.0 0.0 0.0
Fall 2.2 1.8 21.5 0.1

Snowfall Summary

Station: 115768 MONMOUTH, IL

1971-2000 Averages

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
Snow (in) 8.7 5.8 3.3 1.5 0.0 0.0 0.0 0.0 0.0 0.1 2.3 6.8 28.5

Snowfall Extremes

Period of Record: 1893-2006

Month High (in) Year 1-Day Max (in) Date
Jan 22.5 1997 13.0 01-14-1940
Feb 18.0 1944 9.0 02-07-1933
Mar 26.0 1960 10.0 03-16-1960
Apr 17.4 1997 15.0 04-11-1997
May 0.3 1944 0.3 05-05-1944
Jun 0.0 - - -
Jul 0.0 - - -
Aug 0.0 - - -
Sep 1.1 1942 1.1 09-25-1942
Oct 5.5 1967 5.5 10-27-1967
Nov 11.6 1974 7.0 11-30-1974
Dec 19.7 2000 12.0 12-15-1987
Season (Jul-Jun) 59.5 1959-1960 15.0 04-11-1997

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 3.6 2.3 1.3 0.2
Feb 3.6 2.3 1.3 0.2
Mar 1.7 1.2 0.9 0.1
Apr 0.5 0.4 0.3 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 1.5 0.9 0.5 0.0
Dec 3.5 2.4 1.3 0.2
Annual 15.7 10.4 5.9 0.9

Growing Season Summary

Station: 115768 MONMOUTH, 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 7 30 141 386 710 955 1104 1030 772 453 130 20 5746
45 2 10 78 260 555 805 949 876 624 313 67 8 4553
50 0 2 41 156 404 655 794 721 477 195 31 3 3484
55 0 0 19 81 266 505 639 566 335 106 12 0 2533
60 0 0 6 36 152 358 484 411 212 46 2 0 1711
50** 4 18 90 237 444 638 752 695 497 271 72 11 3733

**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 4/19 3/29 4/06 5/05 5/08 10/13 9/22 9/29 11/03 11/03
30 4/16 3/29 4/05 4/28 5/07 10/19 9/21 10/02 11/04 11/07
28 4/07 3/24 3/27 4/23 4/29 10/23 9/30 10/10 11/11 11/16
24 4/05 3/07 3/14 4/14 4/22 11/05 10/20 10/23 11/20 11/29
20 3/20 2/20 3/02 4/08 4/09 11/13 10/20 10/31 12/01 12/19
16 3/12 2/07 2/18 4/01 4/09 11/24 11/02 11/08 12/10 12/27

Length of Growing Season (Days)

Derived from 1971-2000 Averages

Temp °F Median Shortest 10% 90% Longest
32 178 150 154 201 208
30 185 150 168 206 212
28 199 161 182 222 226
24 220 191 198 237 250
20 237 194 215 268 279
16 261 220 233 280 287

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