Precipitation Summary
Station: 114530 JOLIET BRANDON RD DAM, IL
1971-2000 NCDC Normals
| Element | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Ann |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Prec. (in) | 1.58 | 1.64 | 2.46 | 3.75 | 3.87 | 4.22 | 4.34 | 3.82 | 3.14 | 2.70 | 3.00 | 2.44 | 36.96 |
Precipitation Extremes
Period of Record: 1943-2006
| Month | High (in) | Year | Low (in) | Year | 1-Day Max (in) |
Date |
|---|---|---|---|---|---|---|
| Jan | 5.90 | 2005 | 0.05 | 1981 | 1.90 | 01-14-1995 |
| Feb | 5.59 | 1997 | 0.00 | 1987 | 2.75 | 02-21-1997 |
| Mar | 5.37 | 1944 | 0.26 | 1958 | 2.32 | 03-25-1954 |
| Apr | 9.26 | 1947 | 0.53 | 1971 | 4.92 | 04-05-1947 |
| May | 7.62 | 1975 | 0.67 | 1992 | 3.20 | 05-12-2002 |
| Jun | 11.69 | 1993 | 0.38 | 1988 | 5.13 | 06-13-1981 |
| Jul | 17.37 | 1996 | 0.13 | 1991 | 13.60 | 07-18-1996 |
| Aug | 10.05 | 1972 | 0.47 | 1996 | 4.00 | 08-15-1958 |
| Sep | 13.20 | 1961 | 0.04 | 1979 | 3.67 | 09-01-1977 |
| Oct | 8.71 | 1954 | 0.16 | 1964 | 3.75 | 10-11-1954 |
| Nov | 8.18 | 1985 | 0.52 | 1999 | 2.54 | 11-28-1990 |
| Dec | 7.28 | 1982 | 0.27 | 1995 | 3.34 | 12-03-1982 |
| Annual | 50.15 | 1972 | 21.38 | 1963 | 13.60 | 07-18-1996 |
| Winter | 13.09 | 1950 | 1.41 | 1961 | 3.34 | 12-03-1982 |
| Spring | 17.92 | 1973 | 3.61 | 1992 | 4.92 | 04-05-1947 |
| Summer | 22.87 | 1993 | 3.43 | 1991 | 13.60 | 07-18-1996 |
| Fall | 18.31 | 1961 | 3.40 | 1963 | 3.75 | 10-11-1954 |
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 | 10.3 | 4.2 | 0.8 | 0.2 |
| Feb | 8.5 | 4.4 | 0.8 | 0.3 |
| Mar | 10.7 | 5.8 | 1.6 | 0.3 |
| Apr | 11.6 | 7.1 | 2.4 | 0.9 |
| May | 11.1 | 7.5 | 2.8 | 0.8 |
| Jun | 9.8 | 7.1 | 2.8 | 0.9 |
| Jul | 9.1 | 6.1 | 2.8 | 1.1 |
| Aug | 9.4 | 6.0 | 2.6 | 1.0 |
| Sep | 8.4 | 5.3 | 2.0 | 0.8 |
| Oct | 9.0 | 5.0 | 2.0 | 0.6 |
| Nov | 10.8 | 6.1 | 1.9 | 0.7 |
| Dec | 11.1 | 5.1 | 1.5 | 0.4 |
| Annual | 119.8 | 69.5 | 23.9 | 8.1 |
| Winter | 29.8 | 13.7 | 3.1 | 0.9 |
| Spring | 33.4 | 20.4 | 6.8 | 2.0 |
| Summer | 28.3 | 19.1 | 8.1 | 3.0 |
| Fall | 28.2 | 16.4 | 5.9 | 2.1 |
Temperature Summary
Station 114530 JOLIET BRANDON RD DAM, IL
1971-2000 NCDC Normals
| Element | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Ann |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| High °F | 29.9 | 35.2 | 46.8 | 59.5 | 71.6 | 81.3 | 84.6 | 82.4 | 76.0 | 64.1 | 48.3 | 35.2 | 59.6 |
| Low °F | 13.5 | 18.6 | 27.6 | 36.9 | 47.5 | 58.2 | 62.8 | 60.7 | 52.9 | 41.2 | 31.4 | 19.5 | 39.2 |
| Mean °F | 21.7 | 26.9 | 37.2 | 48.2 | 59.6 | 69.8 | 73.7 | 71.6 | 64.5 | 52.7 | 39.9 | 27.4 | 49.4 |
| HDD | 1343 | 1067 | 863 | 505 | 230 | 32 | 4 | 20 | 86 | 391 | 755 | 1168 | 6464 |
| CDD | 0 | 0 | 0 | 2 | 61 | 174 | 272 | 223 | 70 | 7 | 0 | 0 | 809 |
HDD – heating degree days (base 65F); CDD – cooling degree days (base 65F)
Temperature Extremes
Period of Record: 1975-2006
| Month | High Mean °F |
Year | Low Mean °F |
Year | 1-Day Max °F |
Date | 1-Day Min °F |
Date |
|---|---|---|---|---|---|---|---|---|
| Jan | 36.0 | 2006 | 8.5 | 1977 | 65 | 01-05-1997 | -26 | 01-20-1985 |
| Feb | 38.9 | 1998 | 13.5 | 1979 | 73 | 02-26-2000 | -20 | 02-05-1979 |
| Mar | 44.8 | 2000 | 30.1 | 1984 | 86 | 03-30-1986 | -7 | 03-04-2002 |
| Apr | 54.7 | 1977 | 44.0 | 1982 | 92 | 04-26-1986 | 11 | 04-07-1982 |
| May | 68.8 | 1977 | 54.7 | 1997 | 93 | 05-29-1991 | 30 | 05-01-1978 |
| Jun | 74.9 | 1991 | 64.7 | 1982 | 104 | 06-26-1988 | 35 | 06-13-1985 |
| Jul | 78.2 | 1999 | 70.3 | 1992 | 103 | 07-14-1995 | 47 | 07-06-1983 |
| Aug | 78.7 | 1995 | 67.7 | 1992 | 102 | 08-02-1988 | 39 | 08-29-1986 |
| Sep | 70.4 | 2005 | 59.8 | 1993 | 97 | 09-09-1978 | 32 | 09-23-1983 |
| Oct | 57.1 | 2000 | 47.1 | 1987 | 88 | 10-05-2005 | 17 | 10-29-1976 |
| Nov | 50.4 | 2001 | 31.8 | 1976 | 78 | 11-07-1975 | -2 | 11-26-1977 |
| Dec | 36.3 | 1982 | 15.4 | 1983 | 70 | 12-03-1982 | -20 | 12-24-1983 |
| Annual | 54.0 | 1998 | 46.6 | 1989 | 104 | 06-26-1988 | -26 | 01-20-1985 |
| Winter | 32.8 | 1998 | 16.1 | 1979 | 73 | 02-26-1900 | -26 | 01-20-1985 |
| Spring | 55.6 | 1977 | 44.7 | 1996 | 93 | 05-29-1991 | -7 | 03-04-1902 |
| Summer | 76.2 | 1988 | 68.3 | 1992 | 104 | 06-26-1988 | 35 | 06-13-1985 |
| Fall | 61.4 | 2000 | 47.9 | 1976 | 97 | 09-09-1978 | -2 | 11-26-1977 |
Temperature Threshold Climatology
Derived from 1975-2000 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 | 17.6 | 29.2 | 6.6 |
| Feb | 0.0 | 11.3 | 24.5 | 3.3 |
| Mar | 0.0 | 3.5 | 21.4 | 0.0 |
| Apr | 0.1 | 0.1 | 6.8 | 0.0 |
| May | 1.0 | 0.0 | 0.6 | 0.0 |
| Jun | 4.2 | 0.0 | 0.0 | 0.0 |
| Jul | 6.8 | 0.0 | 0.0 | 0.0 |
| Aug | 3.6 | 0.0 | 0.0 | 0.0 |
| Sep | 1.7 | 0.0 | 0.1 | 0.0 |
| Oct | 0.0 | 0.0 | 4.1 | 0.0 |
| Nov | 0.0 | 2.1 | 17.6 | 0.1 |
| Dec | 0.0 | 10.8 | 27.3 | 3.1 |
| Annual | 17.1 | 45.8 | 132.9 | 13.2 |
| Winter | 0.0 | 39.6 | 81.0 | 12.9 |
| Spring | 1.1 | 3.6 | 29.2 | 0.0 |
| Summer | 14.6 | 0.0 | 0.0 | 0.0 |
| Fall | 1.7 | 2.0 | 21.4 | 0.1 |
Snowfall Summary
Station: 114530 JOLIET BRANDON RD DAM, IL
1971-2000 Averages
| Element | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Ann |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Snow (in) | 5.6 | 1.3 | 0.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.3 | 2.4 | 10.3 |
Snowfall Extremes
Period of Record: 1943-2006
| Month | High (in) | Year | 1-Day Max (in) | Date |
|---|---|---|---|---|
| Jan | 18.3 | 1999 | 12.0 | 01-27-1967 |
| Feb | 14.5 | 1963 | 6.0 | 02-24-1994 |
| Mar | 18.1 | 1965 | 8.0 | 03-03-1954 |
| Apr | 2.0 | 1951 | 2.0 | 04-24-1967 |
| May | 0.0 | – | – | – |
| Jun | 0.0 | – | – | – |
| Jul | 0.0 | – | – | – |
| Aug | 0.0 | – | – | – |
| Sep | 0.0 | – | – | – |
| Oct | 3.0 | 1967 | 3.0 | 10-27-1967 |
| Nov | 9.3 | 1951 | 7.0 | 11-07-1951 |
| Dec | 26.0 | 2000 | 8.0 | 12-12-2000 |
| Season (Jul-Jun) | 52.1 | 1951-1952 | 12.0 | 01-27-1967 |
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 | 1.5 | 0.8 | 0.6 | 0.1 |
| Feb | 1.5 | 0.8 | 0.6 | 0.1 |
| Mar | 0.4 | 0.3 | 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 | 1.5 | 0.7 | 0.5 | 0.3 |
| Annual | 3.0 | 1.9 | 1.3 | 0.5 |
Growing Season Summary
Station: 114530 JOLIET BRANDON RD DAM, 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 | 6 | 20 | 102 | 303 | 635 | 907 | 1066 | 1000 | 746 | 398 | 123 | 21 | 5220 |
| 45 | 1 | 6 | 56 | 189 | 482 | 757 | 911 | 845 | 597 | 263 | 64 | 9 | 4097 |
| 50 | 0 | 1 | 28 | 103 | 338 | 608 | 756 | 690 | 450 | 155 | 30 | 4 | 3099 |
| 55 | 0 | 0 | 11 | 51 | 211 | 458 | 601 | 535 | 308 | 79 | 11 | 1 | 2223 |
| 60 | 0 | 0 | 4 | 23 | 115 | 316 | 447 | 380 | 186 | 32 | 2 | 0 | 1479 |
| 50** | 3 | 12 | 64 | 178 | 384 | 596 | 727 | 675 | 468 | 234 | 66 | 11 | 3350 |
**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 | 4/22 | 3/28 | 4/05 | 5/09 | 5/12 | 10/18 | 9/23 | 10/06 | 11/03 | 11/06 |
| 30 | 4/14 | 3/28 | 4/05 | 4/30 | 5/12 | 10/23 | 10/05 | 10/08 | 11/04 | 11/19 |
| 28 | 4/09 | 3/24 | 3/28 | 4/20 | 4/23 | 11/03 | 10/13 | 10/20 | 11/19 | 12/03 |
| 24 | 3/22 | 3/09 | 3/14 | 4/10 | 4/19 | 11/08 | 10/22 | 10/26 | 11/30 | 12/05 |
| 20 | 3/17 | 2/28 | 3/02 | 4/06 | 4/08 | 11/22 | 10/29 | 11/05 | 12/11 | 12/22 |
| 16 | 3/10 | 2/09 | 2/15 | 3/24 | 4/08 | 12/04 | 11/03 | 11/12 | 12/21 | 12/23 |
Length of Growing Season (Days)
Derived from 1975-2000 Averages
| Temp °F | Median | Shortest | 10% | 90% | Longest |
|---|---|---|---|---|---|
| 32 | 177 | 137 | 155 | 210 | 214 |
| 30 | 187 | 159 | 166 | 213 | 225 |
| 28 | 209 | 189 | 196 | 225 | 238 |
| 24 | 225 | 202 | 206 | 256 | 265 |
| 20 | 251 | 212 | 218 | 281 | 284 |
| 16 | 266 | 221 | 236 | 303 | 310 |
Copyright 2007 Illinois State Water Survey
Last Modified: September 11, 2007