Precipitation Summary
Station: 114805 LACON 1 N, IL
1971-2000 NCDC Normals
| Element | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Ann |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Prec. (in) | 1.55 | 1.61 | 3.08 | 3.84 | 4.20 | 4.14 | 4.12 | 3.53 | 3.49 | 2.99 | 3.03 | 2.32 | 37.90 |
Precipitation Extremes
Period of Record: 1950-2006
| Month | High (in) | Year | Low (in) | Year | 1-Day Max (in) |
Date |
|---|---|---|---|---|---|---|
| Jan | 5.92 | 1965 | 0.20 | 1981 | 2.50 | 01-29-2001 |
| Feb | 6.25 | 1997 | 0.08 | 1969 | 3.52 | 02-21-1997 |
| Mar | 6.68 | 1985 | 0.91 | 1966 | 3.12 | 03-04-1985 |
| Apr | 7.58 | 1965 | 0.99 | 1985 | 2.65 | 04-02-1983 |
| May | 10.14 | 1995 | 0.39 | 1992 | 2.35 | 05-27-1996 |
| Jun | 10.10 | 1990 | 0.78 | 1988 | 4.18 | 06-20-1964 |
| Jul | 12.47 | 1992 | 0.32 | 1988 | 5.47 | 07-16-1977 |
| Aug | 8.82 | 1981 | 0.79 | 1974 | 3.25 | 08-31-1980 |
| Sep | 10.87 | 1961 | 0.00 | 1979 | 4.88 | 09-06-1989 |
| Oct | 8.81 | 1991 | 0.03 | 1964 | 4.65 | 10-03-1986 |
| Nov | 9.96 | 1985 | 0.21 | 1999 | 2.77 | 11-18-1985 |
| Dec | 6.12 | 1971 | 0.27 | 1962 | 2.13 | 12-05-1999 |
| Annual | 56.99 | 1970 | 22.91 | 2005 | 5.47 | 07-16-1977 |
| Winter | 9.33 | 2001 | 1.68 | 1977 | 3.52 | 02-21-1997 |
| Spring | 18.55 | 1970 | 4.30 | 1971 | 3.12 | 03-04-1985 |
| Summer | 19.87 | 1981 | 4.07 | 1991 | 5.47 | 07-16-1977 |
| Fall | 16.65 | 1970 | 2.39 | 2002 | 4.88 | 09-06-1989 |
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 | 9.2 | 4.4 | 0.8 | 0.3 |
| Feb | 7.5 | 3.7 | 0.9 | 0.3 |
| Mar | 10.9 | 6.7 | 1.9 | 0.6 |
| Apr | 11.2 | 7.3 | 2.5 | 0.9 |
| May | 12.0 | 7.5 | 2.9 | 1.3 |
| Jun | 9.8 | 6.8 | 2.8 | 1.1 |
| Jul | 9.4 | 6.5 | 2.5 | 1.1 |
| Aug | 8.9 | 6.1 | 2.5 | 0.9 |
| Sep | 8.5 | 5.2 | 2.4 | 0.9 |
| Oct | 8.9 | 5.7 | 2.1 | 0.6 |
| Nov | 10.1 | 6.2 | 2.1 | 0.7 |
| Dec | 9.7 | 5.1 | 1.3 | 0.5 |
| Annual | 116.2 | 71.2 | 24.8 | 9.3 |
| Winter | 26.4 | 13.2 | 3.0 | 1.1 |
| Spring | 34.1 | 21.5 | 7.3 | 2.8 |
| Summer | 28.2 | 19.3 | 7.7 | 3.1 |
| Fall | 27.6 | 17.1 | 6.6 | 2.2 |
Temperature Summary
Station 114805 LACON 1 N, IL
1971-2000 NCDC Normals
| Element | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Ann |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| High °F | 32.0 | 38.0 | 50.6 | 64.1 | 75.2 | 83.9 | 87.2 | 85.4 | 78.6 | 66.5 | 50.3 | 36.8 | 62.4 |
| Low °F | 15.2 | 20.5 | 30.5 | 40.6 | 50.9 | 60.1 | 64.3 | 62.4 | 54.3 | 43.1 | 32.3 | 20.9 | 41.3 |
| Mean °F | 23.6 | 29.3 | 40.6 | 52.4 | 63.1 | 72.0 | 75.8 | 73.9 | 66.5 | 54.8 | 41.3 | 28.9 | 51.9 |
| HDD | 1284 | 1000 | 758 | 388 | 152 | 11 | 2 | 12 | 65 | 328 | 711 | 1120 | 5831 |
| CDD | 0 | 0 | 0 | 9 | 90 | 221 | 334 | 287 | 107 | 12 | 0 | 0 | 1060 |
HDD – heating degree days (base 65F); CDD – cooling degree days (base 65F)
Temperature Extremes
Period of Record: 1950-2006
| Month | High Mean °F |
Year | Low Mean °F |
Year | 1-Day Max °F |
Date | 1-Day Min °F |
Date |
|---|---|---|---|---|---|---|---|---|
| Jan | 38.2 | 2006 | 9.8 | 1977 | 70 | 01-31-1989 | -27 | 01-05-1999 |
| Feb | 39.7 | 1998 | 16.7 | 1979 | 73 | 02-27-1976 | -21 | 02-05-1979 |
| Mar | 47.4 | 2000 | 25.2 | 1960 | 81 | 03-31-1978 | -8 | 03-01-1962 |
| Apr | 59.1 | 1985 | 47.0 | 1982 | 93 | 04-29-1952 | 11 | 04-07-1982 |
| May | 70.3 | 1962 | 57.7 | 1966 | 95 | 05-01-1952 | 22 | 05-10-1966 |
| Jun | 76.4 | 1952 | 67.1 | 1982 | 102 | 06-25-1988 | 36 | 06-11-1972 |
| Jul | 80.6 | 1983 | 70.4 | 1971 | 103 | 07-14-1977 | 44 | 07-30-1971 |
| Aug | 80.2 | 1995 | 68.0 | 1967 | 102 | 08-01-1988 | 38 | 08-28-1986 |
| Sep | 72.3 | 1978 | 62.0 | 1993 | 99 | 09-08-1978 | 28 | 09-23-1974 |
| Oct | 61.2 | 1971 | 47.5 | 1952 | 90 | 10-04-1969 | 16 | 10-29-1952 |
| Nov | 49.7 | 2001 | 33.4 | 1976 | 82 | 11-01-1950 | -3 | 11-26-1977 |
| Dec | 37.8 | 1982 | 16.6 | 1983 | 71 | 12-03-1970 | -24 | 12-23-1989 |
| Annual | 61.1 | 1959 | 49.6 | 1979 | 103 | 07-14-1977 | -27 | 01-05-1999 |
| Winter | 34.1 | 1992 | 18.3 | 1979 | 73 | 02-27-1976 | -27 | 01-05-1999 |
| Spring | 58.0 | 1977 | 46.7 | 1965 | 95 | 05-01-1952 | -8 | 03-01-1962 |
| Summer | 78.2 | 1983 | 70.4 | 1992 | 103 | 07-14-1977 | 36 | 06-11-1972 |
| Fall | 57.4 | 1998 | 49.0 | 1976 | 99 | 09-08-1978 | -3 | 11-26-1977 |
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 | 15.2 | 28.4 | 5.9 |
| Feb | 0.0 | 9.5 | 23.3 | 2.9 |
| Mar | 0.0 | 2.4 | 18.9 | 0.1 |
| Apr | 0.0 | 0.0 | 6.5 | 0.0 |
| May | 1.0 | 0.0 | 0.4 | 0.0 |
| Jun | 6.0 | 0.0 | 0.0 | 0.0 |
| Jul | 10.5 | 0.0 | 0.0 | 0.0 |
| Aug | 7.5 | 0.0 | 0.0 | 0.0 |
| Sep | 2.6 | 0.0 | 0.2 | 0.0 |
| Oct | 0.0 | 0.0 | 4.4 | 0.0 |
| Nov | 0.0 | 1.4 | 16.2 | 0.1 |
| Dec | 0.0 | 9.0 | 26.7 | 2.6 |
| Annual | 28.1 | 36.5 | 122.8 | 11.3 |
| Winter | 0.0 | 33.7 | 78.3 | 11.4 |
| Spring | 1.1 | 2.4 | 25.6 | 0.1 |
| Summer | 24.0 | 0.0 | 0.0 | 0.0 |
| Fall | 2.7 | 1.4 | 20.5 | 0.1 |
Snowfall Summary
Station: 114805 LACON 1 N, IL
1971-2000 Averages
| Element | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Ann |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Snow (in) | 7.5 | 4.9 | 2.6 | 0.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 1.7 | 6.2 | 23.7 |
Snowfall Extremes
Period of Record: 1950-2006
| Month | High (in) | Year | 1-Day Max (in) | Date |
|---|---|---|---|---|
| Jan | 21.3 | 1979 | 12.0 | 01-02-1999 |
| Feb | 13.3 | 1989 | 6.0 | 02-23-1990 |
| Mar | 19.0 | 1960 | 11.0 | 03-13-1991 |
| Apr | 9.2 | 1997 | 8.0 | 04-11-1997 |
| May | 0.0 | – | – | – |
| Jun | 0.0 | – | – | – |
| Jul | 0.0 | – | – | – |
| Aug | 0.0 | – | – | – |
| Sep | 0.0 | – | – | – |
| Oct | 2.0 | 1967 | 2.0 | 10-27-1967 |
| Nov | 12.0 | 1974 | 6.0 | 11-27-1975 |
| Dec | 23.9 | 2000 | 13.0 | 12-01-2006 |
| Season (Jul-Jun) | 44.2 | 1959-1960 | 13.0 | 12-01-2006 |
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 | 3.5 | 1.8 | 1.1 | 0.1 |
| Feb | 3.5 | 1.8 | 1.1 | 0.1 |
| Mar | 1.7 | 0.9 | 0.4 | 0.1 |
| Apr | 0.3 | 0.2 | 0.1 | 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 | 0.0 | 0.0 | 0.0 |
| Nov | 1.2 | 0.6 | 0.3 | 0.1 |
| Dec | 4.3 | 2.0 | 1.3 | 0.2 |
| Annual | 15.8 | 7.9 | 4.5 | 0.7 |
Growing Season Summary
Station: 114805 LACON 1 N, 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 | 9 | 33 | 142 | 384 | 708 | 957 | 1107 | 1049 | 798 | 475 | 150 | 27 | 5804 |
| 45 | 2 | 12 | 80 | 258 | 554 | 807 | 952 | 895 | 648 | 333 | 82 | 12 | 4609 |
| 50 | 0 | 3 | 41 | 155 | 404 | 657 | 798 | 742 | 500 | 211 | 39 | 5 | 3535 |
| 55 | 0 | 0 | 18 | 82 | 266 | 508 | 643 | 588 | 356 | 118 | 15 | 1 | 2582 |
| 60 | 0 | 0 | 6 | 36 | 153 | 360 | 489 | 434 | 228 | 53 | 4 | 0 | 1757 |
| 50** | 4 | 19 | 90 | 236 | 447 | 641 | 753 | 711 | 517 | 292 | 83 | 14 | 3787 |
**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 | 4/23 | 4/02 | 4/08 | 5/09 | 5/15 | 10/11 | 9/20 | 9/23 | 11/02 | 11/04 |
| 30 | 4/14 | 3/27 | 4/03 | 5/03 | 5/08 | 10/17 | 9/20 | 9/23 | 11/02 | 11/04 |
| 28 | 4/11 | 3/15 | 3/28 | 4/28 | 5/08 | 10/20 | 9/23 | 10/05 | 11/09 | 11/20 |
| 24 | 4/05 | 3/06 | 3/14 | 4/13 | 4/18 | 11/03 | 10/13 | 10/20 | 11/19 | 11/25 |
| 20 | 3/20 | 2/21 | 3/07 | 4/09 | 4/13 | 11/13 | 10/20 | 10/26 | 11/29 | 12/11 |
| 16 | 3/09 | 2/07 | 2/14 | 3/27 | 4/07 | 11/28 | 11/03 | 11/09 | 12/15 | 12/23 |
Length of Growing Season (Days)
Derived from 1971-2000 Averages
| Temp °F | Median | Shortest | 10% | 90% | Longest |
|---|---|---|---|---|---|
| 32 | 172 | 139 | 152 | 186 | 208 |
| 30 | 181 | 140 | 167 | 205 | 208 |
| 28 | 194 | 150 | 171 | 212 | 250 |
| 24 | 214 | 189 | 196 | 241 | 259 |
| 20 | 234 | 194 | 210 | 258 | 271 |
| 16 | 264 | 222 | 233 | 286 | 300 |
Copyright 2007 Illinois State Water Survey
Last Modified: September 11, 2007