Precipitation Summary
Station: 114823 LA HARPE, IL
1971-2000 NCDC Normals
| Element | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Ann |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Prec. (in) | 1.47 | 1.68 | 2.86 | 3.82 | 4.58 | 4.38 | 4.54 | 3.54 | 3.99 | 2.85 | 3.15 | 2.28 | 39.14 |
Precipitation Extremes
Period of Record: 1895-2006
| Month | High (in) | Year | Low (in) | Year | 1-Day Max (in) |
Date |
|---|---|---|---|---|---|---|
| Jan | 10.38 | 1897 | 0.08 | 1986 | 4.00 | 01-19-1907 |
| Feb | 4.99 | 1997 | 0.02 | 2006 | 3.41 | 02-21-1997 |
| Mar | 7.66 | 1985 | 0.28 | 1956 | 5.08 | 03-04-1985 |
| Apr | 8.28 | 1964 | 0.76 | 1971 | 4.52 | 04-24-1976 |
| May | 12.57 | 1899 | 0.50 | 1964 | 4.40 | 05-21-1899 |
| Jun | 12.60 | 1905 | 0.49 | 1963 | 10.25 | 06-10-1905 |
| Jul | 14.54 | 1948 | 0.10 | 1916 | 5.02 | 07-25-1948 |
| Aug | 12.36 | 1970 | 0.38 | 1910 | 5.45 | 08-14-1898 |
| Sep | 13.21 | 1970 | 0.12 | 1940 | 4.50 | 09-12-1928 |
| Oct | 13.61 | 1941 | 0.00 | 1964 | 4.74 | 10-03-1986 |
| Nov | 8.45 | 1985 | 0.08 | 1917 | 3.20 | 11-30-2006 |
| Dec | 6.00 | 1982 | 0.23 | 1976 | 3.37 | 12-10-2003 |
| Annual | 51.20 | 1973 | 20.80 | 1988 | 10.25 | 06-10-1905 |
| Winter | 13.20 | 1897 | 1.42 | 1920 | 4.00 | 01-19-1907 |
| Spring | 18.88 | 1899 | 3.05 | 1956 | 5.08 | 03-04-1985 |
| Summer | 25.50 | 1902 | 3.38 | 1936 | 10.25 | 06-10-1905 |
| Fall | 22.79 | 1941 | 1.95 | 1956 | 4.74 | 10-03-1986 |
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 | 6.0 | 3.9 | 0.7 | 0.3 |
| Feb | 5.1 | 3.9 | 0.9 | 0.3 |
| Mar | 7.9 | 6.2 | 1.7 | 0.5 |
| Apr | 9.2 | 7.1 | 2.7 | 0.9 |
| May | 10.8 | 8.2 | 3.0 | 1.3 |
| Jun | 8.7 | 6.7 | 3.0 | 1.2 |
| Jul | 8.3 | 6.4 | 2.8 | 1.5 |
| Aug | 8.4 | 6.4 | 2.5 | 1.1 |
| Sep | 7.5 | 5.9 | 2.8 | 1.0 |
| Oct | 7.7 | 5.4 | 1.6 | 0.7 |
| Nov | 8.1 | 6.3 | 2.4 | 0.5 |
| Dec | 6.7 | 5.1 | 1.2 | 0.5 |
| Annual | 94.6 | 71.7 | 25.4 | 9.8 |
| Winter | 17.9 | 12.9 | 2.8 | 1.0 |
| Spring | 28.0 | 21.6 | 7.4 | 2.7 |
| Summer | 25.4 | 19.5 | 8.3 | 3.8 |
| Fall | 23.3 | 17.7 | 6.9 | 2.3 |
Temperature Summary
Station 114823 LA HARPE, IL
1971-2000 NCDC Normals
| Element | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Ann |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| High °F | 31.7 | 37.6 | 50.0 | 62.4 | 73.3 | 82.7 | 87.0 | 84.7 | 77.3 | 65.9 | 49.6 | 36.5 | 61.6 |
| Low °F | 13.3 | 18.2 | 28.7 | 39.4 | 50.5 | 60.0 | 64.3 | 62.3 | 53.6 | 42.3 | 30.5 | 19.2 | 40.2 |
| Mean °F | 22.5 | 27.9 | 39.4 | 50.9 | 61.9 | 71.4 | 75.7 | 73.5 | 65.5 | 54.1 | 40.1 | 27.9 | 50.9 |
| HDD | 1318 | 1039 | 796 | 429 | 173 | 17 | 1 | 14 | 86 | 350 | 749 | 1152 | 6124 |
| CDD | 0 | 0 | 0 | 6 | 77 | 207 | 331 | 277 | 100 | 11 | 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 | 38.5 | 1933 | 10.3 | 1940 | 70 | 01-07-1907 | -23 | 01-18-1930 |
| Feb | 39.2 | 1930 | 13.8 | 1936 | 76 | 02-24-1930 | -30 | 02-13-1905 |
| Mar | 52.4 | 1946 | 23.9 | 1960 | 88 | 03-23-1910 | -13 | 03-05-1960 |
| Apr | 59.6 | 1896 | 44.9 | 1907 | 94 | 04-10-1930 | 9 | 04-05-1920 |
| May | 70.3 | 1962 | 55.1 | 1990 | 105 | 05-31-1934 | 26 | 05-07-1906 |
| Jun | 80.5 | 1934 | 65.2 | 1916 | 108 | 06-29-1934 | 37 | 06-12-1903 |
| Jul | 84.1 | 1936 | 69.1 | 1924 | 110 | 07-15-1936 | 42 | 07-14-1975 |
| Aug | 82.0 | 1947 | 66.4 | 1915 | 113 | 08-09-1934 | 36 | 08-31-1915 |
| Sep | 74.2 | 1897 | 59.5 | 1993 | 103 | 09-01-1913 | 23 | 09-30-1899 |
| Oct | 66.0 | 1963 | 43.7 | 1925 | 96 | 10-04-2006 | 1 | 10-30-1925 |
| Nov | 50.4 | 1931 | 32.8 | 1996 | 83 | 11-01-1950 | -3 | 11-30-1929 |
| Dec | 39.6 | 1965 | 13.9 | 2000 | 72 | 12-05-1998 | -26 | 12-28-1924 |
| Annual | 56.1 | 1918 | 48.3 | 1996 | 113 | 08-09-1934 | -30 | 02-13-1905 |
| Winter | 36.2 | 1932 | 17.6 | 1936 | 76 | 02-24-1930 | -30 | 02-13-1905 |
| Spring | 57.6 | 1977 | 45.7 | 1960 | 105 | 05-31-1934 | -13 | 03-05-1960 |
| Summer | 80.4 | 1934 | 68.2 | 1915 | 113 | 08-09-1934 | 36 | 08-31-1915 |
| Fall | 61.2 | 1931 | 47.9 | 1976 | 103 | 09-01-1913 | -3 | 11-30-1929 |
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 | 14.9 | 29.7 | 6.6 |
| Feb | 0.0 | 9.1 | 24.8 | 3.4 |
| Mar | 0.0 | 2.4 | 20.3 | 0.2 |
| Apr | 0.1 | 0.0 | 6.9 | 0.0 |
| May | 0.8 | 0.0 | 0.5 | 0.0 |
| Jun | 5.5 | 0.0 | 0.0 | 0.0 |
| Jul | 11.3 | 0.0 | 0.0 | 0.0 |
| Aug | 7.4 | 0.0 | 0.0 | 0.0 |
| Sep | 2.6 | 0.0 | 0.4 | 0.0 |
| Oct | 0.1 | 0.0 | 6.7 | 0.0 |
| Nov | 0.0 | 1.9 | 19.2 | 0.2 |
| Dec | 0.0 | 9.9 | 28.0 | 3.3 |
| Annual | 27.8 | 38.1 | 136.1 | 13.7 |
| Winter | 0.0 | 33.9 | 82.6 | 13.4 |
| Spring | 0.9 | 2.5 | 27.7 | 0.2 |
| Summer | 24.2 | 0.0 | 0.0 | 0.0 |
| Fall | 2.7 | 1.9 | 26.3 | 0.2 |
Snowfall Summary
Station: 114823 LA HARPE, IL
1971-2000 Averages
| Element | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Ann |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Snow (in) | 7.6 | 4.7 | 3.4 | 0.9 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 1.9 | 6.1 | 24.6 |
Snowfall Extremes
Period of Record: 1895-2006
| Month | High (in) | Year | 1-Day Max (in) | Date |
|---|---|---|---|---|
| Jan | 27.0 | 1930 | 10.0 | 01-13-1927 |
| Feb | 13.5 | 1905 | 10.0 | 02-18-1908 |
| Mar | 20.0 | 1960 | 8.0 | 03-09-1998 |
| Apr | 12.0 | 1920 | 12.0 | 04-04-1920 |
| May | 1.5 | 1917 | 1.5 | 05-04-1917 |
| Jun | 0.0 | – | – | – |
| Jul | 0.0 | – | – | – |
| Aug | 0.0 | – | – | – |
| Sep | 3.1 | 1942 | 3.1 | 09-25-1942 |
| Oct | 9.0 | 1916 | 9.0 | 10-20-1916 |
| Nov | 12.0 | 1974 | 8.0 | 11-30-1974 |
| Dec | 19.0 | 2000 | 13.0 | 12-24-1918 |
| Season (Jul-Jun) | 51.5 | 1978-1979 | 13.0 | 12-24-1918 |
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 | 2.4 | 2.1 | 1.2 | 0.1 |
| Feb | 2.4 | 2.1 | 1.2 | 0.1 |
| Mar | 1.7 | 1.6 | 0.7 | 0.1 |
| Apr | 0.3 | 0.3 | 0.2 | 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 | 1.0 | 0.9 | 0.3 | 0.1 |
| Dec | 2.9 | 2.7 | 1.5 | 0.2 |
| Annual | 12.0 | 11.0 | 5.7 | 0.9 |
Growing Season Summary
Station: 114823 LA HARPE, 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 | 7 | 29 | 130 | 352 | 687 | 942 | 1099 | 1026 | 754 | 430 | 125 | 20 | 5606 |
| 45 | 1 | 11 | 70 | 231 | 533 | 792 | 944 | 871 | 605 | 293 | 66 | 8 | 4432 |
| 50 | 0 | 2 | 35 | 135 | 384 | 642 | 789 | 716 | 458 | 180 | 30 | 3 | 3380 |
| 55 | 0 | 0 | 15 | 67 | 248 | 493 | 634 | 561 | 318 | 96 | 11 | 0 | 2450 |
| 60 | 0 | 0 | 4 | 29 | 139 | 347 | 480 | 407 | 199 | 42 | 2 | 0 | 1652 |
| 50** | 6 | 22 | 90 | 221 | 427 | 625 | 739 | 685 | 484 | 273 | 79 | 14 | 3670 |
**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 | 5/03 | 5/11 | 10/11 | 9/21 | 9/24 | 10/24 | 11/03 |
| 30 | 4/13 | 3/25 | 4/03 | 4/28 | 5/10 | 10/18 | 9/23 | 10/02 | 11/04 | 11/09 |
| 28 | 4/09 | 3/24 | 3/27 | 4/22 | 5/06 | 10/21 | 10/01 | 10/05 | 11/06 | 11/12 |
| 24 | 4/05 | 3/15 | 3/17 | 4/14 | 4/18 | 11/02 | 10/08 | 10/20 | 11/19 | 11/22 |
| 20 | 3/24 | 3/03 | 3/12 | 4/10 | 4/13 | 11/12 | 10/20 | 10/28 | 11/27 | 11/30 |
| 16 | 3/12 | 2/07 | 2/11 | 3/31 | 4/07 | 11/21 | 11/02 | 11/07 | 12/08 | 12/21 |
Length of Growing Season (Days)
Derived from 1971-2000 Averages
| Temp °F | Median | Shortest | 10% | 90% | Longest |
|---|---|---|---|---|---|
| 32 | 173 | 137 | 154 | 186 | 207 |
| 30 | 188 | 147 | 164 | 205 | 211 |
| 28 | 196 | 164 | 175 | 214 | 227 |
| 24 | 212 | 189 | 195 | 234 | 239 |
| 20 | 228 | 194 | 213 | 254 | 264 |
| 16 | 260 | 215 | 230 | 286 | 300 |
Copyright 2007 Illinois State Water Survey
Last Modified: September 11, 2007