Official 1981-2010 Climate Normals
City: CAHOKIA
State: IL
ID: 111160
Latitude: 38.5669
Longitude: -90.1942
Elevation: 399.8 ft
Temperature-Related Normals
Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
High: 39.8 45.4 55.6 67.0 75.5 84.0 88.0 87.0 79.6 69.1 56.2 42.6
Mean: 30.7 35.1 45.2 56.3 65.4 74.2 78.4 76.9 68.7 57.4 45.8 33.8
Low: 21.5 24.9 34.7 45.5 55.3 64.5 68.7 66.7 57.8 45.7 35.5 24.9
CDD: 0 0 5 29 103 285 414 369 162 29 3 0
HDD: 1065 836 621 291 90 7 0 2 51 265 577 969
Number of Days
T090: 0.0 0.0 0.0 0.2 0.8 5.3 12.4 10.0 2.8 0.2 0.0 0.0
T100: 0.0 0.0 0.0 0.0 0.0 0.0 0.5 0.5 0.0 0.0 0.0 0.0
T000: 1.2 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.4
T032: 26.1 21.1 12.8 2.0 0.0 0.0 0.0 0.0 0.0 2.4 11.4 23.3
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Annual Values
High Temp: 65.9 F
Mean Temp: 55.7 F
Low Temp: 45.6 F
Cooling DD: 1399
Heating DD: 4774
Days above 90 (T090): 31.6
Days above 100 (T100): 1.1
Days below 0 (T000): 2.0
Days below 32 (T032): 99.2
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Precipitation-Related Normals
Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Prcp: 2.62 2.54 3.34 3.83 4.65 4.10 4.44 3.40 3.40 3.42 3.92 3.07
Snow: 5.0 3.6 1.7 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.6 4.0
Number of Days
P001: 8.1 7.7 10.3 10.6 11.6 9.8 8.5 7.8 6.8 8.4 8.9 9.3
P010: 5.2 5.3 7.0 7.5 8.2 6.7 6.5 5.8 5.0 5.8 6.5 5.9
P100: 0.6 0.6 0.9 0.8 1.1 1.1 1.6 1.0 1.0 1.0 1.0 0.8
S001: 2.7 2.1 0.9 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.3 2.2
S010: 1.7 1.0 0.6 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.2 1.2
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
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Annual Values
Precipitation: 42.73 inches
Snowfall: 15.1 inches
Days precipitation at or above 0 inches (P000): 107.8
Days precipitation at or above 0.10 inches (P010): 75.4
Days Precipitation at or above 1.00 inches (P100): 11.5
Days Snowfall at or above 0.1 inches (S001): 8.3
Days Snowfall at or above 1.0 inches (S010): 4.8
Days Snowfall at or above 10.0 inches (S100): 0.0
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City: CAHOKIA-ST. LOUIS Downtown Airport
State: IL
ID: 003960
Latitude: 38.5714
Longitude: -90.1572
Elevation: 413.0 ft
Temperature-Related Normals
Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
High: 40.7 45.5 56.2 67.5 76.6 85.4 88.4 87.7 80.3 69.2 54.9 42.7
Mean: 31.7 36.1 45.2 55.9 65.8 74.0 77.8 76.2 67.7 57.0 45.1 34.3
Low: 22.7 26.7 34.2 44.3 55.0 62.6 67.2 64.7 55.1 44.7 35.3 26.0
CDD: 0 0 3 24 108 277 397 349 134 28 1 0
HDD: 1032 809 617 297 83 7 0 2 53 277 598 950
Number of Days
T090: 0.0 0.0 0.0 0.2 1.1 8.3 12.6 9.9 3.1 0.2 0.0 0.0
T100: 0.0 0.0 0.0 0.0 0.0 0.1 0.4 0.4 0.0 0.0 0.0 0.0
T000: 0.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1
T032: 25.4 20.3 13.3 2.7 0.0 0.0 0.0 0.0 0.0 2.8 12.3 22.5
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Annual Values
High Temp: 66.3 F
Mean Temp: 55.7 F
Low Temp: 45.0 F
Cooling DD: 1322
Heating DD: 4727
Days above 90 (T090): 35.3
Days above 100 (T100): 0.9
Days below 0 (T000): 0.8
Days below 32 (T032): 99.4
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Precipitation-Related Pseudonormals
For stations with short records, linear combinations of normals from nearby sites were used
to compute so-called pseudonormals.
Normal Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Prcp: 2.39 2.10 3.17 4.05 4.95 4.17 3.59 3.15 3.18 3.39 3.76 3.04
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Annual Values
Precipitation: 40.94 inches
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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
