Official 1981-2010 Climate Normals City: LISLE-MORTON ARBORETUM State: IL ID: 115097 Latitude: 41.8128 Longitude: -88.0728 Elevation: 679.9 ft Temperature-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 High: 30.7 35.5 46.9 59.6 69.7 80.1 83.8 81.2 74.8 62.5 48.5 35.1 Mean: 22.7 26.2 36.5 48.3 58.5 69.1 72.8 70.6 62.9 50.9 38.6 27.0 Low: 14.7 16.9 26.1 37.0 47.2 58.0 61.7 60.0 50.9 39.3 28.6 18.8 CDD: 0 0 0 1 25 155 245 194 55 7 0 0 HDD: 1311 1086 884 503 228 34 5 20 119 444 793 1179 Number of Days T090: 0.0 0.0 0.0 0.0 0.0 1.8 2.8 2.0 0.5 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: 3.7 0.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 T032: 27.3 26.0 22.7 8.6 0.3 0.0 0.0 0.0 0.0 6.8 21.4 28.9 ------------------------------------------------------------------------------------------ Annual Values High Temp: 59.1 F Mean Temp: 48.8 F Low Temp: 38.4 F Cooling DD: 683 Heating DD: 6607 Days above 90 (T090): 7.1 Days above 100 (T100): 0.0 Days below 0 (T000): 5.4 Days below 32 (T032): 142.0 ------------------------------------------------------------------------------------------ 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: 1.87 1.85 2.46 3.60 4.04 4.22 3.70 4.27 3.51 3.08 3.33 2.59 ------------------------------------------------------------------------------------------ Annual Values Precipitation: 38.52 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