Official 1981-2010 Climate Normals City: PARK FOREST State: IL ID: 116616 Latitude: 41.4947 Longitude: -87.6803 Elevation: 709.8 ft Temperature-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec High: 30.6 35.0 46.3 59.4 70.2 80.1 83.9 81.9 75.2 63.0 48.3 34.9 Mean: 23.1 27.0 37.7 49.6 60.1 70.1 74.4 72.5 65.0 52.9 40.4 27.6 Low: 15.6 19.0 29.1 39.8 50.0 60.0 65.0 63.1 54.8 42.9 32.4 20.3 CDD: 0 0 1 10 54 191 296 242 100 12 0 0 HDD: 1299 1064 847 472 206 40 4 10 100 386 740 1159 Number of Days T090: 0.0 0.0 0.0 0.0 0.7 3.1 4.9 3.1 1.1 0.0 0.0 0.0 T100: 0.0 0.0 0.0 0.0 0.0 0.1 0.3 0.0 0.0 0.0 0.0 0.0 T000: 4.2 2.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.8 T032: 28.4 25.3 19.7 5.3 0.2 0.0 0.0 0.0 0.1 3.1 14.7 26.5 ------------------------------------------------------------------------------------------ Annual Values High Temp: 59.2 F Mean Temp: 50.1 F Low Temp: 41.1 F Cooling DD: 907 Heating DD: 6326 Days above 90 (T090): 13.0 Days above 100 (T100): 0.4 Days below 0 (T000): 8.1 Days below 32 (T032): 123.1 ------------------------------------------------------------------------------------------ Precipitation-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Prcp: 1.99 1.85 2.61 3.77 4.47 4.56 4.55 4.50 3.18 3.35 3.58 2.62 Snow: 8.4 7.9 4.4 0.7 0.0 0.0 0.0 0.0 0.0 0.2 0.6 5.6 Number of Days P001: 9.8 8.7 10.8 11.8 11.9 9.7 9.3 8.9 8.9 10.2 10.9 11.2 P010: 4.9 4.4 6.1 7.3 7.6 6.4 6.5 5.7 5.7 6.4 6.1 5.7 P100: 0.3 0.2 0.4 0.8 1.1 1.3 1.2 1.5 0.7 0.8 0.9 0.3 S001: 5.7 4.5 2.6 0.4 0.0 0.0 0.0 0.0 0.0 0.1 0.8 4.4 S010: 4.0 3.0 1.7 0.3 0.0 0.0 0.0 0.0 0.0 0.1 0.3 2.8 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: 41.03 inches Snowfall: 27.8 inches Days precipitation at or above 0 inches (P000): 122.1 Days precipitation at or above 0.10 inches (P010): 72.8 Days Precipitation at or above 1.00 inches (P100): 9.5 Days Snowfall at or above 0.1 inches (S001): 18.5 Days Snowfall at or above 1.0 inches (S010): 12.2 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