Official 1981-2010 Climate Normals City: MARENGO State: IL ID: 115326 Latitude: 42.2928 Longitude: -88.6469 Elevation: 814.8 ft Temperature-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec High: 28.9 33.4 45.0 58.8 70.2 80.3 83.6 81.9 74.9 62.4 47.1 32.7 Mean: 20.4 24.8 35.5 47.7 58.5 68.4 72.4 70.7 62.9 50.8 38.2 24.5 Low: 11.9 16.2 26.0 36.5 46.9 56.6 61.3 59.5 50.9 39.2 29.2 16.3 CDD: 0 0 0 7 38 150 239 195 75 8 0 0 HDD: 1382 1125 915 527 238 47 9 18 138 448 806 1255 Number of Days T090: 0.0 0.0 0.0 0.0 0.5 3.3 4.9 3.4 0.6 0.0 0.0 0.0 T100: 0.0 0.0 0.0 0.0 0.0 0.2 0.1 0.1 0.0 0.0 0.0 0.0 T000: 5.9 4.0 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1 3.6 T032: 29.3 25.4 22.8 9.2 0.7 0.0 0.0 0.0 0.3 6.6 18.7 28.5 ------------------------------------------------------------------------------------------ Annual Values High Temp: 58.4 F Mean Temp: 48.0 F Low Temp: 37.6 F Cooling DD: 712 Heating DD: 6908 Days above 90 (T090): 12.6 Days above 100 (T100): 0.4 Days below 0 (T000): 13.9 Days below 32 (T032): 141.3 ------------------------------------------------------------------------------------------ Precipitation-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Prcp: 1.28 1.37 2.08 3.43 4.05 4.32 3.82 4.68 3.03 2.83 2.59 2.03 Snow: 8.0 7.8 3.7 0.9 0.1 0.0 0.0 0.0 0.0 0.1 1.7 8.7 Number of Days P001: 7.7 6.5 8.4 10.8 11.2 9.7 9.6 9.4 8.1 8.5 8.9 8.9 P010: 3.3 3.6 4.4 7.0 7.7 6.5 6.3 7.0 5.7 5.6 5.6 4.3 P100: 0.1 0.2 0.4 0.6 0.9 1.2 1.1 1.4 0.6 0.7 0.5 0.2 S001: 5.1 3.9 1.9 0.5 0.1 0.0 0.0 0.0 0.0 0.1 1.1 4.2 S010: 3.6 2.9 1.2 0.5 0.1 0.0 0.0 0.0 0.0 0.1 0.9 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: 35.51 inches Snowfall: 31.0 inches Days precipitation at or above 0 inches (P000): 107.7 Days precipitation at or above 0.10 inches (P010): 67.0 Days Precipitation at or above 1.00 inches (P100): 7.9 Days Snowfall at or above 0.1 inches (S001): 16.9 Days Snowfall at or above 1.0 inches (S010): 12.1 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