Official 1981-2010 Climate Normals City: GRIGGSVILLE State: IL ID: 113717 Latitude: 39.7378 Longitude: -90.7086 Elevation: 627.8 ft Temperature-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec High: 34.1 39.1 50.6 63.3 73.2 81.8 85.6 84.6 77.9 65.9 51.5 37.6 Mean: 25.7 29.9 40.5 52.4 62.4 71.7 75.2 73.7 66.0 54.2 41.8 29.3 Low: 17.3 20.8 30.3 41.5 51.5 61.6 64.8 62.8 54.2 42.4 32.1 21.0 CDD: 0 0 1 12 55 215 318 275 116 16 0 0 HDD: 1218 981 762 390 137 14 2 5 85 352 696 1107 Number of Days T090: 0.0 0.0 0.0 0.0 0.3 2.7 7.1 6.8 2.7 0.1 0.0 0.0 T100: 0.0 0.0 0.0 0.0 0.0 0.1 0.1 0.8 0.0 0.0 0.0 0.0 T000: 3.3 1.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.7 T032: 28.3 22.8 18.6 4.6 0.3 0.0 0.0 0.0 0.3 3.9 15.9 25.9 ------------------------------------------------------------------------------------------ Annual Values High Temp: 62.2 F Mean Temp: 52.0 F Low Temp: 41.8 F Cooling DD: 1008 Heating DD: 5749 Days above 90 (T090): 19.7 Days above 100 (T100): 1.0 Days below 0 (T000): 6.3 Days below 32 (T032): 120.6 ------------------------------------------------------------------------------------------ Precipitation-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Prcp: 1.90 1.85 2.84 3.71 4.52 4.38 4.35 3.00 3.39 2.93 3.34 2.37 Snow: 4.0 4.9 2.2 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.3 5.9 Number of Days P001: 6.8 7.1 8.9 9.9 10.7 9.4 8.6 8.6 7.2 8.1 8.7 8.2 P010: 3.2 4.5 6.1 6.7 7.1 6.8 6.0 5.7 5.1 5.2 5.8 5.0 P100: 0.5 0.3 0.5 1.0 1.2 1.2 1.4 0.6 1.0 0.7 1.0 0.8 S001: 3.4 3.1 1.0 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.3 3.2 S010: 1.5 2.0 0.6 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.1 2.2 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: 38.58 inches Snowfall: 17.7 inches Days precipitation at or above 0 inches (P000): 102.2 Days precipitation at or above 0.10 inches (P010): 67.2 Days Precipitation at or above 1.00 inches (P100): 10.2 Days Snowfall at or above 0.1 inches (S001): 11.2 Days Snowfall at or above 1.0 inches (S010): 6.5 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