Official 1981-2010 Climate Normals City: CHARLESTON State: IL ID: 111436 Latitude: 39.4761 Longitude: -88.1653 Elevation: 649.8 ft Temperature-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec High: 36.4 41.7 53.2 65.7 75.0 83.8 86.4 85.0 79.1 67.1 53.3 39.7 Mean: 28.4 33.1 43.4 54.7 64.2 73.1 76.2 74.6 67.8 56.3 44.4 32.1 Low: 20.5 24.4 33.5 43.7 53.3 62.4 66.1 64.3 56.4 45.5 35.6 24.5 CDD: 0 0 3 21 87 255 349 302 144 24 1 0 HDD: 1133 894 674 330 113 12 0 3 61 294 618 1020 Number of Days T090: 0.0 0.0 0.0 0.0 0.5 5.3 7.7 6.8 2.2 0.1 0.0 0.0 T100: 0.0 0.0 0.0 0.0 0.0 0.0 0.1 0.1 0.0 0.0 0.0 0.0 T000: 2.3 0.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 T032: 25.5 21.3 14.6 3.9 0.2 0.0 0.0 0.0 0.0 2.6 11.3 22.6 ------------------------------------------------------------------------------------------ Annual Values High Temp: 64.0 F Mean Temp: 54.1 F Low Temp: 44.3 F Cooling DD: 1186 Heating DD: 5153 Days above 90 (T090): 22.5 Days above 100 (T100): 0.3 Days below 0 (T000): 4.3 Days below 32 (T032): 102.0 ------------------------------------------------------------------------------------------ Precipitation-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Prcp: 2.49 2.51 2.89 4.29 4.62 4.35 4.47 2.93 3.24 3.76 3.97 3.15 Snow: 7.5 4.4 1.8 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.7 2.6 Number of Days P001: 9.1 8.2 10.6 11.4 11.5 9.0 9.0 8.0 7.1 8.7 10.2 10.6 P010: 5.1 5.0 6.6 8.1 8.2 6.4 6.2 5.3 4.9 5.7 7.1 6.7 P100: 0.6 0.5 0.5 0.9 1.1 1.1 1.3 0.9 0.8 1.1 1.0 0.7 S001: 4.7 2.7 1.4 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.5 3.6 S010: 3.5 1.7 0.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.2 2.0 S100: 0.1 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: 42.67 inches Snowfall: 17.2 inches Days precipitation at or above 0 inches (P000): 113.4 Days precipitation at or above 0.10 inches (P010): 75.3 Days Precipitation at or above 1.00 inches (P100): 10.5 Days Snowfall at or above 0.1 inches (S001): 13.1 Days Snowfall at or above 1.0 inches (S010): 8.2 Days Snowfall at or above 10.0 inches (S100): 0.1 ------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------ 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