Precipitation Summary
Station: 115430 MATTOON, IL
1971-2000 NCDC Normals
| Element | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Ann |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Prec. (in) | 2.03 | 2.08 | 3.06 | 3.84 | 3.95 | 4.21 | 4.16 | 3.25 | 3.06 | 3.02 | 3.71 | 2.84 | 39.21 |
Precipitation Extremes
Period of Record: 1893-2006
| Month | High (in) | Year | Low (in) | Year | 1-Day Max (in) |
Date |
|---|---|---|---|---|---|---|
| Jan | 9.91 | 1950 | 0.02 | 1986 | 3.34 | 01-03-1950 |
| Feb | 5.30 | 1950 | 0.33 | 1963 | 2.88 | 02-14-1949 |
| Mar | 7.88 | 1904 | 0.52 | 1999 | 3.31 | 03-25-1904 |
| Apr | 9.71 | 1984 | 0.49 | 1971 | 3.50 | 04-21-1984 |
| May | 11.00 | 1902 | 0.73 | 1895 | 3.22 | 05-31-1902 |
| Jun | 14.83 | 1902 | 0.52 | 1988 | 3.95 | 06-28-1957 |
| Jul | 10.07 | 1896 | 0.79 | 1999 | 3.85 | 07-20-1973 |
| Aug | 8.29 | 1981 | 0.14 | 1971 | 4.86 | 08-26-1992 |
| Sep | 9.64 | 1969 | 0.33 | 1985 | 5.03 | 09-01-2003 |
| Oct | 8.83 | 2001 | 0.17 | 1904 | 3.40 | 10-13-2001 |
| Nov | 10.02 | 1985 | 0.08 | 1904 | 3.43 | 11-01-1992 |
| Dec | 7.98 | 1967 | 0.16 | 1955 | 3.04 | 12-07-1966 |
| Annual | 53.79 | 1950 | 18.54 | 1895 | 5.03 | 09-01-2003 |
| Winter | 19.64 | 1950 | 1.89 | 1963 | 3.34 | 01-03-1950 |
| Spring | 22.62 | 2002 | 4.24 | 1895 | 3.50 | 04-21-1984 |
| Summer | 19.40 | 1973 | 3.94 | 1984 | 4.86 | 08-26-1992 |
| Fall | 18.47 | 1993 | 3.58 | 1953 | 5.03 | 09-01-2003 |
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 | 8.7 | 4.9 | 1.4 | 0.3 |
| Feb | 7.9 | 4.6 | 1.1 | 0.4 |
| Mar | 11.0 | 7.0 | 2.2 | 0.6 |
| Apr | 11.8 | 7.5 | 2.4 | 0.7 |
| May | 10.8 | 7.3 | 2.6 | 1.1 |
| Jun | 10.2 | 6.8 | 3.0 | 1.2 |
| Jul | 8.8 | 6.5 | 3.3 | 1.0 |
| Aug | 8.1 | 5.5 | 2.0 | 1.1 |
| Sep | 7.3 | 5.0 | 2.0 | 1.0 |
| Oct | 8.3 | 5.5 | 2.2 | 0.8 |
| Nov | 10.3 | 6.3 | 2.5 | 1.1 |
| Dec | 9.3 | 5.2 | 1.6 | 0.6 |
| Annual | 112.5 | 72.2 | 26.4 | 10.1 |
| Winter | 25.8 | 14.8 | 4.2 | 1.3 |
| Spring | 33.6 | 21.8 | 7.2 | 2.5 |
| Summer | 27.1 | 18.8 | 8.3 | 3.4 |
| Fall | 25.9 | 16.7 | 6.7 | 2.9 |
Temperature Summary
Station 115430 MATTOON, IL
1971-2000 NCDC Normals
| Element | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Ann |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| High °F | 33.0 | 38.6 | 50.2 | 62.4 | 73.3 | 82.8 | 86.0 | 84.2 | 78.2 | 66.0 | 50.6 | 38.0 | 61.9 |
| Low °F | 16.6 | 21.1 | 31.7 | 42.2 | 53.2 | 62.7 | 66.3 | 64.2 | 55.9 | 44.7 | 33.2 | 22.5 | 42.9 |
| Mean °F | 24.8 | 29.9 | 41.0 | 52.3 | 63.3 | 72.8 | 76.2 | 74.2 | 67.1 | 55.4 | 41.9 | 30.3 | 52.4 |
| HDD | 1245 | 985 | 745 | 385 | 156 | 12 | 0 | 9 | 61 | 318 | 694 | 1077 | 5687 |
| CDD | 0 | 0 | 0 | 5 | 103 | 244 | 345 | 295 | 123 | 19 | 0 | 0 | 1134 |
HDD – heating degree days (base 65F); CDD – cooling degree days (base 65F)
Temperature Extremes
Period of Record: 1893-2002
| Month | High Mean °F |
Year | Low Mean °F |
Year | 1-Day Max °F |
Date | 1-Day Min °F |
Date |
|---|---|---|---|---|---|---|---|---|
| Jan | 38.0 | 1990 | 11.5 | 1977 | 70 | 01-25-1950 | -23 | 01-20-1985 |
| Feb | 40.6 | 1998 | 18.3 | 1979 | 74 | 02-24-2000 | -20 | 02-13-1905 |
| Mar | 52.0 | 1905 | 25.5 | 1960 | 85 | 03-31-1981 | -8 | 03-06-1960 |
| Apr | 60.6 | 2001 | 46.6 | 1950 | 90 | 04-29-1895 | 17 | 04-03-1987 |
| May | 70.6 | 1977 | 57.5 | 1961 | 95 | 05-20-1987 | 28 | 05-10-1966 |
| Jun | 78.1 | 1952 | 65.0 | 1903 | 105 | 06-26-1954 | 36 | 06-12-1903 |
| Jul | 83.8 | 1901 | 72.1 | 1971 | 111 | 07-14-1954 | 46 | 07-11-1898 |
| Aug | 81.5 | 1900 | 68.8 | 1967 | 104 | 08-02-1901 | 40 | 08-29-1986 |
| Sep | 72.7 | 1998 | 61.1 | 1949 | 103 | 09-05-1954 | 28 | 09-30-1899 |
| Oct | 67.0 | 1900 | 48.9 | 1976 | 92 | 10-02-1953 | 19 | 10-26-1962 |
| Nov | 50.8 | 2001 | 34.8 | 1959 | 82 | 11-01-1950 | -2 | 11-24-1950 |
| Dec | 38.6 | 1965 | 18.2 | 1983 | 71 | 12-15-1948 | -20 | 12-22-1989 |
| Annual | 59.2 | 1898 | 50.3 | 1979 | 111 | 07-14-1954 | -23 | 01-20-1985 |
| Winter | 36.7 | 1906 | 20.9 | 1978 | 74 | 02-24-1900 | -23 | 01-20-1985 |
| Spring | 58.7 | 1905 | 46.8 | 1960 | 95 | 05-20-1987 | -8 | 03-06-1960 |
| Summer | 78.4 | 1901 | 70.7 | 1950 | 111 | 07-14-1954 | 36 | 06-12-1903 |
| Fall | 61.4 | 1900 | 49.6 | 1976 | 103 | 09-05-1954 | -2 | 11-24-1950 |
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 | 14.0 | 28.2 | 3.4 |
| Feb | 0.0 | 8.5 | 22.3 | 1.9 |
| Mar | 0.0 | 1.9 | 17.1 | 0.1 |
| Apr | 0.0 | 0.0 | 5.0 | 0.0 |
| May | 0.9 | 0.0 | 0.1 | 0.0 |
| Jun | 6.2 | 0.0 | 0.0 | 0.0 |
| Jul | 9.9 | 0.0 | 0.0 | 0.0 |
| Aug | 7.0 | 0.0 | 0.0 | 0.0 |
| Sep | 2.7 | 0.0 | 0.0 | 0.0 |
| Oct | 0.0 | 0.0 | 3.0 | 0.0 |
| Nov | 0.0 | 1.3 | 14.6 | 0.0 |
| Dec | 0.0 | 8.4 | 25.7 | 1.6 |
| Annual | 26.8 | 33.9 | 115.5 | 6.9 |
| Winter | 0.0 | 31.0 | 76.2 | 6.9 |
| Spring | 0.9 | 1.9 | 22.2 | 0.1 |
| Summer | 23.1 | 0.0 | 0.0 | 0.0 |
| Fall | 2.7 | 1.3 | 17.6 | 0.0 |
Snowfall Summary
Station: 115430 MATTOON, IL
1971-2000 Averages
| Element | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Ann |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Snow (in) | 6.8 | 3.4 | 2.0 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 1.0 | 4.7 | 18.0 |
Snowfall Extremes
Period of Record: 1893-2006
| Month | High (in) | Year | 1-Day Max (in) | Date |
|---|---|---|---|---|
| Jan | 22.6 | 1997 | 11.0 | 01-09-1997 |
| Feb | 13.5 | 1993 | 8.0 | 02-24-1974 |
| Mar | 19.0 | 1978 | 10.0 | 03-07-1978 |
| Apr | 1.0 | 1977 | 1.0 | 04-08-1989 |
| May | 0.0 | – | – | – |
| Jun | 0.0 | – | – | – |
| Jul | 0.0 | – | – | – |
| Aug | 0.0 | – | – | – |
| Sep | 0.0 | – | – | – |
| Oct | 0.0 | – | – | – |
| Nov | 9.5 | 1980 | 7.5 | 11-27-1980 |
| Dec | 21.5 | 1973 | 10.0 | 12-19-1973 |
| Season (Jul-Jun) | 49.7 | 1977-1978 | 11.0 | 01-09-1997 |
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 | 1.7 | 1.3 | 0.8 | 0.1 |
| Feb | 1.7 | 1.3 | 0.8 | 0.1 |
| Mar | 1.0 | 0.8 | 0.4 | 0.1 |
| Apr | 0.1 | 0.1 | 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 | 0.6 | 0.3 | 0.2 | 0.1 |
| Dec | 2.2 | 1.7 | 1.0 | 0.3 |
| Annual | 8.8 | 6.9 | 3.9 | 0.7 |
Growing Season Summary
Station: 115430 MATTOON, 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 | 17 | 43 | 161 | 393 | 732 | 988 | 1127 | 1067 | 821 | 487 | 165 | 31 | 6037 |
| 45 | 6 | 17 | 91 | 264 | 578 | 838 | 972 | 912 | 671 | 344 | 93 | 12 | 4803 |
| 50 | 1 | 5 | 47 | 158 | 426 | 688 | 817 | 757 | 522 | 219 | 46 | 4 | 3698 |
| 55 | 0 | 1 | 21 | 84 | 287 | 538 | 662 | 602 | 378 | 125 | 19 | 1 | 2723 |
| 60 | 0 | 0 | 7 | 37 | 169 | 389 | 507 | 447 | 247 | 58 | 5 | 0 | 1872 |
| 50** | 10 | 25 | 97 | 231 | 455 | 664 | 777 | 729 | 530 | 289 | 89 | 17 | 3918 |
**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 | 4/14 | 3/24 | 3/31 | 5/05 | 5/12 | 10/19 | 10/02 | 10/07 | 11/03 | 11/04 |
| 30 | 4/10 | 3/18 | 3/28 | 4/22 | 5/12 | 10/24 | 10/02 | 10/07 | 11/12 | 11/22 |
| 28 | 4/08 | 3/14 | 3/21 | 4/14 | 4/22 | 11/03 | 10/03 | 10/11 | 11/21 | 11/28 |
| 24 | 3/27 | 2/22 | 3/12 | 4/10 | 4/18 | 11/11 | 10/21 | 10/27 | 11/30 | 12/10 |
| 20 | 3/18 | 2/22 | 3/05 | 4/06 | 4/09 | 11/21 | 10/24 | 11/07 | 12/10 | 12/21 |
| 16 | 3/07 | 1/15 | 2/07 | 3/20 | 3/27 | 12/07 | 11/02 | 11/12 | 12/22 | 1/12 |
Length of Growing Season (Days)
Derived from 1971-2000 Averages
| Temp °F | Median | Shortest | 10% | 90% | Longest |
|---|---|---|---|---|---|
| 32 | 183 | 158 | 164 | 208 | 225 |
| 30 | 198 | 164 | 176 | 220 | 229 |
| 28 | 207 | 177 | 190 | 235 | 255 |
| 24 | 227 | 195 | 208 | 258 | 263 |
| 20 | 251 | 220 | 225 | 276 | 288 |
| 16 | 274 | 236 | 251 | 308 | 339 |
Copyright 2007 Illinois State Water Survey
Last Modified: September 11, 2007