Official 1981-2010 Climate Normals City: CHICAGO AURORA MUNI State: IL ID: 004808 Latitude: 41.7700 Longitude: -88.4814 Elevation: 709.8 ft Temperature-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec High: 29.1 33.7 47.0 60.0 70.6 80.1 83.5 81.2 74.9 62.2 47.8 32.8 Mean: 20.8 24.9 37.0 48.5 58.8 68.8 71.7 70.1 62.8 50.6 38.1 25.1 Low: 12.6 16.2 26.9 37.0 47.1 57.5 59.8 59.0 50.7 39.0 28.4 17.5 CDD: 0 0 0 3 38 155 215 173 63 8 0 0 HDD: 1368 1121 870 498 228 41 9 15 129 454 807 1235 Number of Days T090: 0.0 0.0 0.0 0.0 0.5 2.9 4.1 1.6 0.6 0.0 0.0 0.0 T100: 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 T000: 5.9 3.4 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 4.0 T032: 29.3 26.3 22.5 9.5 1.1 0.0 0.0 0.0 0.1 7.3 19.8 26.7 ------------------------------------------------------------------------------------------ Annual Values High Temp: 58.7 F Mean Temp: 48.2 F Low Temp: 37.7 F Cooling DD: 655 Heating DD: 6776 Days above 90 (T090): 9.6 Days above 100 (T100): 0.0 Days below 0 (T000): 13.6 Days below 32 (T032): 142.6 ------------------------------------------------------------------------------------------ Precipitation-Related Pseudonormals For stations with short records, linear combinations of normals from nearby sites were used to compute so-called pseudonormals. Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Prcp: 1.47 1.62 2.23 3.30 4.26 4.01 4.19 4.12 3.44 3.12 3.14 1.96 ------------------------------------------------------------------------------------------ Annual Values Precipitation: 36.86 inches ------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------ 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