Official 1981-2010 Climate Normals
City: CHICAGO OHARE AP
State: IL
ID: 094846
Latitude: 41.9950
Longitude: -87.9336
Elevation: 658.0 ft
Temperature-Related Normals
Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
High: 31.0 35.3 46.6 59.0 70.0 79.7 84.1 81.9 74.8 62.3 48.2 34.8
Mean: 23.8 27.7 37.9 48.9 59.1 68.9 74.0 72.4 64.6 52.5 40.3 27.7
Low: 16.5 20.1 29.2 38.8 48.3 58.1 63.9 62.9 54.3 42.8 32.4 20.7
CDD: 0 0 1 9 44 165 283 238 92 11 0 0
HDD: 1279 1044 841 492 225 48 4 9 105 397 741 1155
Number of Days
T090: 0.0 0.0 0.0 0.0 0.5 3.0 5.9 3.6 1.0 0.0 0.0 0.0
T100: 0.0 0.0 0.0 0.0 0.0 0.1 0.3 0.0 0.0 0.0 0.0 0.0
T000: 3.8 1.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.5
T032: 28.0 24.0 19.6 6.3 0.3 0.0 0.0 0.0 0.1 3.5 14.0 26.0
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Annual Values
High Temp: 59.1 F
Mean Temp: 49.9 F
Low Temp: 40.8 F
Cooling DD: 842
Heating DD: 6339
Days above 90 (T090): 14.0
Days above 100 (T100): 0.4
Days below 0 (T000): 7.1
Days below 32 (T032): 121.8
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Precipitation-Related Normals
Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Prcp: 1.73 1.79 2.50 3.38 3.68 3.45 3.70 4.90 3.21 3.15 3.15 2.25
Snow: 10.8 9.1 5.6 1.2 0.0 0.0 0.0 0.0 0.0 0.3 1.2 8.5
Number of Days
P001: 10.5 8.8 11.1 12.0 11.6 10.2 9.8 9.8 8.3 10.2 10.8 11.0
P010: 4.7 4.4 5.5 6.4 7.2 5.9 6.0 6.7 5.4 5.9 6.0 5.0
P100: 0.1 0.3 0.4 0.8 0.8 0.9 1.0 1.5 0.8 0.6 0.8 0.3
S001: 8.2 6.1 4.3 0.9 0.0 0.0 0.0 0.0 0.0 0.2 1.7 7.1
S010: 3.7 2.8 1.7 0.3 0.0 0.0 0.0 0.0 0.0 0.1 0.4 2.6
S100: 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
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Annual Values
Precipitation: 36.89 inches
Snowfall: 36.7 inches
Days precipitation at or above 0 inches (P000): 124.1
Days precipitation at or above 0.10 inches (P010): 69.1
Days Precipitation at or above 1.00 inches (P100): 8.3
Days Snowfall at or above 0.1 inches (S001): 28.5
Days Snowfall at or above 1.0 inches (S010): 11.6
Days Snowfall at or above 10.0 inches (S100): 0.1
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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
