Historical Climate Data

Precipitation Summary

Station: 113384 GENESEO, IL

1971-2000 NCDC Normals

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
Prec. (in) 1.52 1.58 2.69 3.74 4.21 4.20 3.90 4.32 3.29 3.01 2.82 2.15 37.43

Precipitation Extremes

Period of Record: 1895-2006


Month
High (in)
Year
Low (in)
Year 		1-Day
Max (in)
Date
Jan 4.90 1897 0.20 1961 3.05 01-12-1960
Feb 3.97 1997 0.04 1969 1.86 02-21-1985
Mar 6.15 1898 0.17 1958 2.03 03-17-1998
Apr 7.31 1973 0.67 1946 3.01 04-21-1973
May 12.19 1974 0.55 1992 3.93 05-16-1974
Jun 11.58 1990 0.60 1991 6.00 06-24-1898
Jul 12.85 1992 0.35 1991 5.00 07-30-1904
Aug 13.69 1987 0.52 1976 6.57 08-25-1898
Sep 12.61 1926 0.05 1979 5.20 09-03-1926
Oct 9.36 1998 0.08 1964 4.75 10-17-1998
Nov 6.70 1985 0.21 1904 3.31 11-17-1928
Dec 4.69 1987 0.00 1939 2.56 12-02-1982
             
Annual 56.93 1898 19.24 2005 6.57 08-25-1898
Winter 8.43 1974 0.78 2003 3.05 01-12-1960
Spring 19.47 1973 2.85 1934 3.93 05-16-1974
Summer 24.19 1898 4.37 1991 6.57 08-25-1898
Fall 18.48 1961 3.41 1952 5.20 09-03-1926

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 8.4 4.1 0.6 0.2
Feb 6.8 3.6 0.9 0.2
Mar 9.7 5.5 1.7 0.7
Apr 10.5 6.7 2.4 1.0
May 11.2 7.3 2.5 1.2
Jun 10.1 6.8 2.7 1.2
Jul 9.6 6.4 2.6 1.0
Aug 9.3 6.4 2.6 1.3
Sep 7.9 5.2 2.4 0.8
Oct 8.7 5.3 1.9 0.6
Nov 9.9 5.9 1.8 0.5
Dec 8.5 4.8 1.3 0.4
         
Annual 110.9 68.1 23.5 9.2
Winter 23.8 12.5 2.8 0.9
Spring 31.5 19.5 6.6 2.9
Summer 29.1 19.7 7.9 3.5
Fall 26.6 16.4 6.1 1.9

Temperature Summary

Station 113384 GENESEO, IL

1971-2000 NCDC Normals

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
High °F 28.7 34.4 47.2 61.1 73.1 82.4 85.7 83.2 75.7 63.3 46.9 33.4 59.6
Low °F 13.4 19.3 29.5 40.2 51.6 61.3 65.7 63.5 54.9 43.2 31.1 19.2 41.1
Mean °F 21.1 26.9 38.4 50.7 62.4 71.9 75.7 73.4 65.3 53.3 39.0 26.3 50.4
HDD 1363 1068 826 436 167 14 1 13 80 372 780 1201 6321
CDD 0 0 0 5 84 218 334 271 88 9 0 0 1009

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 35.0 2006 7.5 1977 66 01-31-1989 -23 01-10-1982
Feb 37.5 1998 13.8 1979 71 02-25-2000 -25 02-13-1905
Mar 45.3 2000 22.1 1960 87 03-29-1986 -13 03-01-1962
Apr 56.9 1896 42.7 1907 92 04-25-1986 12 04-07-1982
May 69.5 1977 55.1 1907 95 05-26-1985 26 05-10-1966
Jun 77.5 1971 65.5 1903 101 06-19-1971 39 06-16-1961
Jul 82.7 1901 70.6 1992 107 07-24-1901 47 07-07-1965
Aug 79.1 1995 67.4 1967 103 08-17-1988 40 08-28-1986
Sep 72.9 1906 60.1 1993 99 09-08-1971 25 09-30-1899
Oct 64.6 1963 46.8 1976 92 10-03-1997 19 10-30-1988
Nov 49.6 2001 30.5 1976 79 11-01-2000 -7 11-29-1976
Dec 35.7 1965 12.9 1983 70 12-04-1998 -20 12-24-1983
                 
Annual 58.9 1956 47.6 1978 107 07-24-1901 -25 02-13-1905
Winter 32.2 2002 15.4 1979 71 02-25-1900 -25 02-13-1905
Spring 56.2 1977 44.9 1960 95 05-26-1985 -13 03-01-1962
Summer 77.2 1988 69.2 1992 107 07-24-1901 39 06-16-1961
Fall 58.4 1963 46.6 1976 99 09-08-1971 -7 11-29-1976

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 18.1 29.6 6.7
Feb 0.0 11.8 24.8 3.3
Mar 0.0 3.6 20.8 0.1
Apr 0.1 0.2 6.1 0.0
May 1.2 0.0 0.2 0.0
Jun 5.2 0.0 0.0 0.0
Jul 8.7 0.0 0.0 0.0
Aug 5.6 0.0 0.0 0.0
Sep 1.9 0.0 0.2 0.0
Oct 0.1 0.0 3.9 0.0
Nov 0.0 3.0 18.0 0.2
Dec 0.0 12.5 28.0 3.5
         
Annual 22.9 49.2 131.3 13.8
Winter 0.0 42.3 82.5 13.5
Spring 1.3 3.7 26.7 0.1
Summer 19.5 0.0 0.0 0.0
Fall 2.0 3.0 22.1 0.2

Snowfall Summary

Station: 113384 GENESEO, IL

1971-2000 Averages

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
Snow (in) 8.4 5.5 3.2 1.2 0.0 0.0 0.0 0.0 0.0 0.1 2.1 7.2 27.7

Snowfall Extremes

Period of Record: 1895-2006

Month High (in) Year 1-Day Max (in) Date
Jan 20.9 1979 16.0 01-03-1971
Feb 20.8 1960 12.0 02-03-1901
Mar 18.0 1972 9.0 03-02-2002
Apr 10.5 1970 8.5 04-02-1975
May 0.0 - - -
Jun 0.0 - - -
Jul 0.0 - - -
Aug 0.0 - - -
Sep 0.0 - - -
Oct 6.0 1898 6.0 10-25-1898
Nov 11.3 1974 8.5 11-26-1975
Dec 24.8 2000 14.5 12-15-1987
Season (Jul-Jun) 53.7 1978-1979 16.0 01-03-1971

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 3.3 1.9 0.9 0.3
Feb 3.3 1.9 0.9 0.3
Mar 2.0 1.3 0.6 0.1
Apr 0.3 0.2 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 1.6 0.8 0.5 0.1
Dec 3.9 2.4 1.3 0.3
Annual 16.2 9.2 4.8 1.2

Growing Season Summary

Station: 113384 GENESEO, 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 4 19 108 338 690 954 1102 1025 750 413 107 15 5526
45 1 6 58 218 536 804 947 870 601 277 54 6 4381
50 0 1 29 123 387 654 793 715 454 167 23 2 3352
55 0 0 12 61 252 504 638 561 314 89 8 0 2443
60 0 0 4 28 144 357 483 406 193 38 2 0 1659
50** 3 11 69 198 420 634 754 692 471 238 56 8 3557

**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 3/26 4/05 5/05 5/17 10/12 9/23 9/27 11/02 11/10
30 4/15 3/24 3/31 4/28 5/17 10/19 10/02 10/07 11/05 11/16
28 4/08 3/24 3/27 4/23 4/29 10/30 10/02 10/13 11/15 11/17
24 4/04 3/14 3/17 4/11 4/18 11/07 10/10 10/20 11/19 11/28
20 3/18 2/20 2/27 4/07 4/09 11/15 10/20 11/03 12/02 12/21
16 3/09 2/09 2/18 3/27 4/07 11/27 11/01 11/10 12/13 12/27

Length of Growing Season (Days)

Derived from 1971-2000 Averages

Temp °F Median Shortest 10% 90% Longest
32 176 137 155 205 217
30 187 161 169 211 226
28 203 161 182 223 232
24 218 189 201 237 248
20 247 194 218 274 283
16 261 220 236 292 310

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