Chicago Botanical Garden Climate Normals

Official 1981-2010 Climate Normals

City: CHICAGO BOTANICAL GDN
State: IL
ID: 111497
Latitude: 42.1406
Longitude: -87.7867
Elevation:  629.8 ft

Temperature-Related Normals

Normal    Jan    Feb    Mar    Apr    May    Jun    Jul    Aug    Sep    Oct    Nov    Dec
High:    31.6   35.7   45.4   56.7   67.5   77.7   82.6   81.3   74.4   62.3   48.9   35.7
Mean:    23.7   27.4   36.8   47.3   57.3   67.3   72.8   71.8   64.1   52.1   40.8   28.0
 Low:    15.9   19.1   28.2   37.9   47.2   57.0   63.1   62.3   53.9   41.9   32.8   20.4
 CDD:       0      0      1      9     36    142    252    223     87      9      0      0
 HDD:    1279   1053    875    540    274     71      9     12    113    408    725   1145

Number of Days
T090:     0.0    0.0    0.0    0.0    0.6    3.1    4.9    3.7    1.1    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    1.9    0.1    0.0    0.0    0.0    0.0    0.0    0.0    0.0    0.0    1.6
T032:    28.5   25.1   21.0    6.8    0.4    0.0    0.0    0.0    0.1    3.9   13.9   26.2
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Annual Values

 High Temp:    58.4 F
 Mean Temp:    49.2 F
  Low Temp:    40.1 F
Cooling DD:     759
Heating DD:    6503

Days above  90 (T090):    13.3
Days above 100 (T100):     0.3
Days below   0 (T000):     7.4
Days below  32 (T032):   125.9
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Precipitation-Related Normals

Normal    Jan    Feb    Mar    Apr    May    Jun    Jul    Aug    Sep    Oct    Nov    Dec
Prcp:    1.81   1.73   2.37   3.58   4.01   3.67   3.63   4.77   3.48   3.24   3.06   2.40
Snow:    11.2    7.9    5.4    0.9    0.0    0.0    0.0    0.0    0.0    0.1    1.4    6.5

Number of Days
P001:     9.8    7.9   10.3   12.6   12.2   10.7    9.5    9.6    9.3   10.5   10.4   10.5
P010:     5.2    4.2    5.7    7.0    7.5    6.7    6.1    6.5    5.9    5.8    5.8    5.7
P100:     0.2    0.2    0.3    0.7    0.9    0.8    1.0    1.2    1.0    0.7    0.6    0.3
S001:     6.5    5.0    3.1    0.7    0.0    0.0    0.0    0.0    0.0    0.1    1.3    5.6
S010:     3.5    2.8    1.7    0.2    0.0    0.0    0.0    0.0    0.0    0.1    0.6    2.6
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
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Annual Values

Precipitation:   37.75 inches
     Snowfall:    33.4 inches

   Days precipitation at or above 0 inches (P000):   123.3
Days precipitation at or above 0.10 inches (P010):    72.1
Days Precipitation at or above 1.00 inches (P100):     7.9
      Days Snowfall at or above 0.1 inches (S001):    22.3
      Days Snowfall at or above 1.0 inches (S010):    11.5
     Days Snowfall at or above 10.0 inches (S100):     0.0

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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