Official 1981-2010 Climate Normals City: GLADSTONE DAM 18 State: IL ID: 113455 Latitude: 40.8825 Longitude: -91.0242 Elevation: 537.9 ft Temperature-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec High: 32.0 36.8 48.6 61.9 72.2 81.9 85.3 83.6 76.5 64.5 49.8 35.8 Mean: 23.6 28.1 39.1 51.6 62.1 71.9 75.6 73.8 65.8 54.0 41.1 27.5 Low: 15.2 19.4 29.5 41.3 51.9 62.0 65.9 64.0 55.2 43.5 32.4 19.3 CDD: 0 0 1 8 61 226 329 277 106 12 0 0 HDD: 1283 1033 805 410 153 18 1 4 80 353 717 1161 Number of Days T090: 0.0 0.0 0.0 0.0 0.6 3.9 6.3 4.8 1.1 0.1 0.0 0.0 T100: 0.0 0.0 0.0 0.0 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.0 T000: 4.1 2.3 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 T032: 29.0 24.8 19.6 3.9 0.2 0.0 0.0 0.0 0.1 1.9 14.3 27.7 ------------------------------------------------------------------------------------------ Annual Values High Temp: 60.9 F Mean Temp: 51.3 F Low Temp: 41.7 F Cooling DD: 1020 Heating DD: 6018 Days above 90 (T090): 16.8 Days above 100 (T100): 0.1 Days below 0 (T000): 8.4 Days below 32 (T032): 121.5 ------------------------------------------------------------------------------------------ Precipitation-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Prcp: 1.22 1.47 2.49 3.62 4.38 4.65 4.19 3.75 3.60 2.79 2.62 1.97 Number of Days P001: 6.7 7.0 8.4 9.9 11.3 10.1 8.9 8.8 7.2 8.2 8.6 8.0 P010: 3.0 3.7 5.1 6.8 8.1 7.5 6.3 6.4 5.3 4.9 5.3 4.3 P100: 0.2 0.2 0.5 0.8 1.1 1.4 1.4 1.0 1.1 0.8 0.5 0.4 ------------------------------------------------------------------------------------------ Annual Values Precipitation: 36.75 inches Days precipitation at or above 0 inches (P000): 103.1 Days precipitation at or above 0.10 inches (P010): 66.7 Days Precipitation at or above 1.00 inches (P100): 9.4 ------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------ 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