Official 1981-2010 Climate Normals City: CHICAGO BOTANICAL GDN State: IL ID: 111497 Latitude: 42.1406 Longitude: -87.7867 Elevation: 629.8 ft Temperature-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec High: 31.6 35.7 45.4 56.7 67.5 77.7 82.6 81.3 74.4 62.3 48.9 35.7 Mean: 23.7 27.4 36.8 47.3 57.3 67.3 72.8 71.8 64.1 52.1 40.8 28.0 Low: 15.9 19.1 28.2 37.9 47.2 57.0 63.1 62.3 53.9 41.9 32.8 20.4 CDD: 0 0 1 9 36 142 252 223 87 9 0 0 HDD: 1279 1053 875 540 274 71 9 12 113 408 725 1145 Number of Days T090: 0.0 0.0 0.0 0.0 0.6 3.1 4.9 3.7 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: 3.8 1.9 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.6 T032: 28.5 25.1 21.0 6.8 0.4 0.0 0.0 0.0 0.1 3.9 13.9 26.2 ------------------------------------------------------------------------------------------ Annual Values High Temp: 58.4 F Mean Temp: 49.2 F Low Temp: 40.1 F Cooling DD: 759 Heating DD: 6503 Days above 90 (T090): 13.3 Days above 100 (T100): 0.3 Days below 0 (T000): 7.4 Days below 32 (T032): 125.9 ------------------------------------------------------------------------------------------ Precipitation-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Prcp: 1.81 1.73 2.37 3.58 4.01 3.67 3.63 4.77 3.48 3.24 3.06 2.40 Snow: 11.2 7.9 5.4 0.9 0.0 0.0 0.0 0.0 0.0 0.1 1.4 6.5 Number of Days P001: 9.8 7.9 10.3 12.6 12.2 10.7 9.5 9.6 9.3 10.5 10.4 10.5 P010: 5.2 4.2 5.7 7.0 7.5 6.7 6.1 6.5 5.9 5.8 5.8 5.7 P100: 0.2 0.2 0.3 0.7 0.9 0.8 1.0 1.2 1.0 0.7 0.6 0.3 S001: 6.5 5.0 3.1 0.7 0.0 0.0 0.0 0.0 0.0 0.1 1.3 5.6 S010: 3.5 2.8 1.7 0.2 0.0 0.0 0.0 0.0 0.0 0.1 0.6 2.6 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: 37.75 inches Snowfall: 33.4 inches Days precipitation at or above 0 inches (P000): 123.3 Days precipitation at or above 0.10 inches (P010): 72.1 Days Precipitation at or above 1.00 inches (P100): 7.9 Days Snowfall at or above 0.1 inches (S001): 22.3 Days Snowfall at or above 1.0 inches (S010): 11.5 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