Official 1981-2010 Climate Normals City: ROCK ISLAND L&D State: IL ID: 117391 Latitude: 41.5194 Longitude: -90.5644 Elevation: 567.8 ft Temperature-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec High: 31.8 36.5 48.9 62.3 72.6 81.5 84.8 83.0 76.5 64.0 49.4 34.5 Mean: 24.1 28.6 40.0 52.5 63.1 72.5 76.3 74.4 67.1 54.7 41.5 27.6 Low: 16.3 20.8 31.0 42.7 53.6 63.6 67.8 65.8 57.6 45.4 33.6 20.7 CDD: 0 0 1 14 75 241 351 295 130 19 1 0 HDD: 1269 1018 777 389 134 14 0 4 69 338 706 1159 Number of Days T090: 0.0 0.0 0.0 0.0 0.7 3.2 6.1 4.2 1.5 0.1 0.0 0.0 T100: 0.0 0.0 0.0 0.0 0.0 0.0 0.1 0.1 0.0 0.0 0.0 0.0 T000: 3.6 1.7 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.6 T032: 28.3 24.2 16.5 3.3 0.1 0.0 0.0 0.0 0.0 1.6 12.2 25.7 ------------------------------------------------------------------------------------------ Annual Values High Temp: 60.6 F Mean Temp: 52.0 F Low Temp: 43.3 F Cooling DD: 1128 Heating DD: 5879 Days above 90 (T090): 15.9 Days above 100 (T100): 0.2 Days below 0 (T000): 6.9 Days below 32 (T032): 112.0 ------------------------------------------------------------------------------------------ Precipitation-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Prcp: 1.35 1.52 2.65 3.44 4.57 5.00 4.06 4.14 2.99 2.95 2.46 1.93 Number of Days P001: 9.8 8.6 9.9 11.3 12.7 11.9 9.5 9.9 8.1 9.5 10.5 10.4 P010: 3.5 3.8 5.3 6.9 7.7 7.8 6.2 6.5 4.6 4.7 5.1 4.8 P100: 0.1 0.3 0.5 0.9 1.6 1.5 1.3 1.3 0.7 0.6 0.2 0.2 ------------------------------------------------------------------------------------------ Annual Values Precipitation: 37.06 inches Days precipitation at or above 0 inches (P000): 122.1 Days precipitation at or above 0.10 inches (P010): 66.9 Days Precipitation at or above 1.00 inches (P100): 9.2 ------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------ 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