Official 1981-2010 Climate Normals City: DECATUR WTP State: IL ID: 112193 Latitude: 39.8289 Longitude: -88.9506 Elevation: 619.9 ft Temperature-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec High: 36.0 41.1 53.1 66.0 75.9 84.5 87.4 86.1 80.0 67.7 53.1 39.4 Mean: 27.5 32.2 42.7 54.4 64.2 73.3 76.5 75.1 67.8 56.2 43.8 31.2 Low: 19.1 23.2 32.3 42.9 52.5 62.0 65.6 64.1 55.6 44.7 34.4 23.1 CDD: 0 0 2 19 88 259 357 317 147 25 1 0 HDD: 1161 920 693 336 112 12 0 4 63 298 639 1046 Number of Days T090: 0.0 0.0 0.0 0.1 0.9 6.3 9.6 7.9 3.3 0.1 0.0 0.0 T100: 0.0 0.0 0.0 0.0 0.0 0.0 0.3 0.4 0.0 0.0 0.0 0.0 T000: 2.7 1.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.2 T032: 26.6 22.0 15.8 3.7 0.1 0.0 0.0 0.0 0.2 3.2 13.1 24.4 ------------------------------------------------------------------------------------------ Annual Values High Temp: 64.3 F Mean Temp: 53.8 F Low Temp: 43.4 F Cooling DD: 1216 Heating DD: 5284 Days above 90 (T090): 28.1 Days above 100 (T100): 0.8 Days below 0 (T000): 5.1 Days below 32 (T032): 109.2 ------------------------------------------------------------------------------------------ Precipitation-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Prcp: 2.14 2.00 2.59 3.67 4.79 4.50 3.98 3.77 3.14 3.25 3.71 2.78 Snow: 4.8 4.2 1.7 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.2 4.9 Number of Days P001: 8.5 7.3 9.7 10.6 12.1 9.9 9.2 7.3 7.5 8.7 9.4 9.7 P010: 4.5 4.1 6.3 6.6 7.6 6.6 6.2 5.2 4.7 5.6 6.2 5.6 P100: 0.6 0.5 0.4 0.9 1.3 1.3 1.2 1.2 0.8 1.0 0.9 0.4 S001: 3.7 2.6 0.9 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.3 2.6 S010: 2.2 1.5 0.6 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.1 1.8 S100: 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 ------------------------------------------------------------------------------------------ Annual Values Precipitation: 40.32 inches Snowfall: 16.0 inches Days precipitation at or above 0 inches (P000): 109.9 Days precipitation at or above 0.10 inches (P010): 69.2 Days Precipitation at or above 1.00 inches (P100): 10.5 Days Snowfall at or above 0.1 inches (S001): 10.3 Days Snowfall at or above 1.0 inches (S010): 6.3 Days Snowfall at or above 10.0 inches (S100): 0.0 ------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------ KEY: High - average daily high temperature, degrees F Mean - average daily mean temperature, degrees F Low - average daily low temperature, degrees F CDD - cooling degree days, base 50F HDD - heating degree days, base 50F T090 - number of Days with Temperatures above 90 degrees F T100 - number of Days with Temperatures above 100 degrees F T000 - number of Days with Temperatures below 0 degrees F T032 - number of Days with Temperatures below 32 degrees F Prcp - precipitation, inches Snow - snowfall, inches P001 - number of Days with Precipitation of 0.01 inches or more P010 - number of Days with Precipitation of 0.10 inches or more P100 - number of Days with Precipitation of 1.00 inches or more S001 - number of Days with Snowfall of 0.1 inches or more S010 - number of Days with Snowfall of 1.0 inches or more S100 - number of Days with Snowfall of 10.0 inches or more Page Source: Dr. Jim Angel, State Climatologist Illinois State Water Survey Prairie Research Institute University of Illinois Data Source: NOAA National Climatic Data Center