Official 1981-2010 Climate Normals City: ROCKFORD AP State: IL ID: 094822 Latitude: 42.1928 Longitude: -89.0931 Elevation: 729.8 ft Temperature-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec High: 29.5 34.2 46.9 60.7 71.8 81.1 84.5 82.4 75.4 62.7 47.6 33.2 Mean: 21.5 25.9 37.2 49.4 60.1 69.8 73.8 71.9 63.9 51.7 38.9 25.4 Low: 13.5 17.7 27.5 38.1 48.4 58.5 63.0 61.3 52.4 40.7 30.3 17.7 CDD: 0 0 0 8 47 175 274 223 84 9 0 0 HDD: 1348 1093 862 476 198 31 3 11 117 422 782 1226 Number of Days T090: 0.0 0.0 0.0 0.0 0.6 3.4 5.7 4.0 1.1 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: 5.5 2.9 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.9 T032: 29.0 25.0 21.8 7.5 0.5 0.0 0.0 0.0 0.3 5.1 16.8 27.4 ------------------------------------------------------------------------------------------ Annual Values High Temp: 59.3 F Mean Temp: 49.2 F Low Temp: 39.2 F Cooling DD: 820 Heating DD: 6569 Days above 90 (T090): 14.9 Days above 100 (T100): 0.2 Days below 0 (T000): 11.6 Days below 32 (T032): 133.5 ------------------------------------------------------------------------------------------ Precipitation-Related Normals Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Prcp: 1.37 1.41 2.32 3.35 4.02 4.65 3.95 4.59 3.35 2.67 2.58 1.98 Snow: 10.2 7.7 4.8 0.9 0.0 0.0 0.0 0.0 0.0 0.1 1.7 11.3 Number of Days P001: 9.4 8.2 10.5 11.3 12.2 10.4 9.4 9.7 8.3 9.4 10.2 10.2 P010: 4.0 3.6 5.1 6.4 7.2 7.2 6.4 6.5 5.3 5.3 5.3 5.0 P100: 0.1 0.2 0.5 0.8 1.2 1.3 0.9 1.2 0.8 0.5 0.5 0.2 S001: 8.2 5.8 4.1 1.0 0.0 0.0 0.0 0.0 0.0 0.1 1.9 7.7 S010: 3.3 2.3 1.5 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.5 3.1 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: 36.24 inches Snowfall: 36.7 inches Days precipitation at or above 0 inches (P000): 119.2 Days precipitation at or above 0.10 inches (P010): 67.3 Days Precipitation at or above 1.00 inches (P100): 8.2 Days Snowfall at or above 0.1 inches (S001): 28.8 Days Snowfall at or above 1.0 inches (S010): 11.1 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