Historical Climate Data

Precipitation Summary

Station: 117487 ROSICLARE 5 NW, IL

1971-2000 NCDC Normals

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
Prec. (in) 3.48 3.68 4.71 4.75 5.02 4.19 4.22 3.49 3.24 3.22 4.41 4.29 48.70

Precipitation Extremes

Period of Record: 1968-2006


Month
High (in)
Year
Low (in)
Year 		1-Day
Max (in)
Date
Jan 9.15 1969 0.77 1984 2.79 01-30-1969
Feb 10.42 1989 0.87 1983 3.31 02-15-1990
Mar 11.00 1997 1.80 1971 4.10 03-02-1997
Apr 13.22 1983 1.38 1988 4.69 04-15-1972
May 12.36 1990 1.26 1994 3.38 05-07-2003
Jun 12.72 1969 0.56 1972 5.02 06-23-1969
Jul 8.76 1989 1.16 2003 4.42 07-02-1989
Aug 13.63 1985 0.44 1976 6.14 08-24-1985
Sep 9.89 2006 0.00 2004 3.02 09-23-2006
Oct 7.70 1985 0.33 2000 3.90 10-07-1998
Nov 9.05 1988 0.63 1989 3.16 11-24-1973
Dec 10.74 1982 0.66 1980 4.96 12-03-1982
             
Annual 68.44 1985 35.69 1999 6.14 08-24-1985
Winter 19.49 1979 4.50 1977 4.96 12-03-1982
Spring 25.42 1983 7.40 1971 4.69 04-15-1972
Summer 27.44 1985 5.15 1991 6.14 08-24-1985
Fall 20.68 1988 4.80 1999 3.90 10-07-1998

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 8.0 6.1 2.4 0.9
Feb 7.7 6.0 2.6 1.1
Mar 10.8 8.4 3.4 1.3
Apr 10.1 7.7 3.1 1.2
May 10.3 8.1 3.8 1.4
Jun 8.5 6.4 3.0 1.3
Jul 7.6 5.7 2.8 1.4
Aug 6.4 5.0 2.2 1.0
Sep 6.8 5.0 2.4 0.9
Oct 6.7 5.0 2.4 1.0
Nov 8.8 6.6 3.1 1.4
Dec 8.7 6.8 3.2 1.1
         
Annual 100.4 76.9 34.5 14.0
Winter 24.4 18.9 8.3 3.1
Spring 31.2 24.2 10.3 3.9
Summer 22.5 17.1 8.0 3.7
Fall 22.2 16.7 7.9 3.3

Temperature Summary

Station 117487 ROSICLARE 5 NW, IL

1971-2000 NCDC Normals

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
High °F 40.9 47.1 57.4 67.7 75.8 83.5 87.4 86.6 80.0 70.0 56.9 45.6 66.6
Low °F 20.8 23.9 33.1 42.1 51.7 60.3 65.0 63.1 54.9 42.6 34.1 25.2 43.1
Mean °F 30.9 35.5 45.3 54.9 63.8 71.9 76.2 74.9 67.5 56.3 45.5 35.4 54.8
HDD 1058 826 611 313 132 9 0 5 59 287 587 918 4805
CDD 0 0 0 10 95 217 348 310 133 18 1 0 1132

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

Temperature Extremes

Period of Record: 1968-2006


Month 		High
Mean °F
Year 		Low
Mean °F
Year 		1-Day
Max °F
Date 		1-Day
Min °F
Date
Jan 42.3 1990 19.3 1977 72 01-24-1972 -22 01-19-1994
Feb 45.8 1976 24.7 1978 77 02-29-1972 -12 02-04-1996
Mar 54.0 1973 38.1 1996 84 03-18-1982 3 03-05-1978
Apr 62.2 1981 49.4 1997 90 04-21-1987 16 04-03-1987
May 69.9 1991 59.9 1997 92 05-29-1969 31 05-16-1997
Jun 76.5 1971 67.9 2003 100 06-23-1988 39 06-05-1990
Jul 80.4 1980 73.9 1996 102 07-30-1999 47 07-15-1987
Aug 80.3 1980 70.8 1992 101 08-03-1987 36 08-29-1986
Sep 76.0 1970 63.8 1974 100 09-05-1999 32 09-24-1989
Oct 64.1 1971 49.9 1987 90 10-01-1998 18 10-08-1987
Nov 53.4 1999 38.6 1976 84 11-02-2000 3 11-13-1986
Dec 45.6 1984 24.3 2000 76 12-02-1982 -17 12-22-1989
                 
Annual 59.7 1968 53.3 1987 102 07-30-1999 -22 01-19-1994
Winter 39.6 2005 28.1 1978 77 02-29-1972 -22 01-19-1994
Spring 60.9 1977 51.9 1996 92 05-29-1969 3 03-05-1978
Summer 78.2 1980 72.4 1992 102 07-30-1999 36 08-29-1986
Fall 62.0 1973 52.7 1976 100 09-05-1999 3 11-13-1986

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 7.3 24.7 1.6
Feb 0.0 3.2 19.6 0.6
Mar 0.0 0.6 13.5 0.0
Apr 0.1 0.0 4.9 0.0
May 0.3 0.0 0.2 0.0
Jun 5.2 0.0 0.0 0.0
Jul 12.7 0.0 0.0 0.0
Aug 10.1 0.0 0.0 0.0
Sep 3.6 0.0 0.1 0.0
Oct 0.0 0.0 4.2 0.0
Nov 0.0 0.1 12.5 0.0
Dec 0.0 3.7 21.8 0.5
         
Annual 32.0 15.0 102.5 2.8
Winter 0.0 14.2 66.1 2.7
Spring 0.4 0.6 18.8 0.0
Summer 28.0 0.0 0.0 0.0
Fall 3.6 0.1 17.0 0.0

Snowfall Summary

Station: 117487 ROSICLARE 5 NW, IL

1971-2000 Averages

Element Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann
Snow (in) 4.1 3.1 1.0 0.1 0.0 0.0 0.0 0.0 0.0 0.2 0.1 1.5 10.1

Snowfall Extremes

Period of Record: 1968-2006

Month High (in) Year 1-Day Max (in) Date
Jan 26.5 1985 9.8 01-16-1978
Feb 16.8 1993 6.5 02-11-1985
Mar 11.0 1970 9.5 03-17-1970
Apr 4.0 1971 4.0 04-06-1971
May 0.0 - - -
Jun 0.0 - - -
Jul 0.0 - - -
Aug 0.0 - - -
Sep 0.0 - - -
Oct 4.5 1993 4.5 10-30-1993
Nov 3.0 1969 3.0 11-19-1969
Dec 8.4 1984 8.4 12-05-1984
Season (Jul-Jun) 43.9 1984-1985 9.8 01-16-1978

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 1.3 1.1 0.6 0.2
Feb 1.3 1.1 0.6 0.2
Mar 0.5 0.5 0.2 0.0
Apr 0.0 0.0 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 0.1 0.0 0.0 0.0
Dec 0.9 0.7 0.3 0.0
Annual 5.1 3.6 2.1 0.4

Growing Season Summary

Station: 117487 ROSICLARE 5 NW, 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 52 98 265 485 767 990 1150 1102 854 535 250 84 6500
45 23 49 165 346 613 840 995 948 704 388 154 41 5160
50 9 20 92 224 460 690 840 793 554 256 85 18 3962
55 3 6 44 129 313 540 685 638 407 149 40 6 2906
60 0 1 17 63 185 391 530 483 272 70 14 1 1994
50** 33 67 172 311 494 673 791 754 564 350 154 51 4329

**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 4/16 3/24 4/02 5/06 5/15 10/21 9/23 10/01 11/06 11/13
30 4/10 3/20 3/24 4/22 4/29 10/24 10/05 10/08 11/08 11/13
28 4/06 3/13 3/18 4/20 4/23 10/27 10/06 10/12 11/16 11/29
24 3/25 3/02 3/08 4/11 4/12 11/14 10/13 10/26 12/05 12/22
20 3/10 2/03 2/17 3/25 4/11 12/01 11/01 11/04 12/20 12/22
16 2/17 1/11 2/01 3/19 4/02 12/08 11/03 11/09 12/24 1/13

Length of Growing Season (Days)

Derived from 1971-2000 Averages

Temp °F Median Shortest 10% 90% Longest
32 182 140 157 209 215
30 204 167 182 222 233
28 213 175 184 235 246
24 234 199 207 270 271
20 268 220 235 292 302
16 290 222 243 312 345

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