Mount Vernon Climate Normals

Official 1981-2010 Climate Normals

City: MT VERNON 3
State: IL
ID: 115943
Latitude: 38.3483
Longitude: -88.8533
Elevation:  490.0 ft

Temperature-Related Normals

Normal    Jan    Feb    Mar    Apr    May    Jun    Jul    Aug    Sep    Oct    Nov    Dec
High:    38.1   43.1   53.5   64.9   73.8   82.9   86.3   85.6   78.6   67.4   54.5   41.3
Mean:    29.5   33.6   43.5   54.2   63.7   72.9   76.6   75.1   67.2   55.6   44.7   32.6
 Low:    20.9   24.2   33.4   43.6   53.6   62.9   66.9   64.6   55.8   43.8   34.8   23.9
 CDD:       0      0      2     18     79    249    360    316    134     20      1      0
 HDD:    1100    878    670    341    120     12      1      3     68    311    612   1004

Number of Days
T090:     0.0    0.0    0.0    0.0    0.1    3.7    7.5    7.5    2.1    0.1    0.0    0.0
T100:     0.0    0.0    0.0    0.0    0.0    0.1    0.1    0.2    0.0    0.0    0.0    0.0
T000:     1.4    0.8    0.0    0.0    0.0    0.0    0.0    0.0    0.0    0.0    0.0    1.1
T032:    26.0   21.6   14.8    3.6    0.0    0.0    0.0    0.0    0.1    4.3   12.6   23.9
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Annual Values

 High Temp:    64.3 F
 Mean Temp:    54.2 F
  Low Temp:    44.1 F
Cooling DD:    1179
Heating DD:    5119

Days above  90 (T090):    21.0
Days above 100 (T100):     0.4
Days below   0 (T000):     3.3
Days below  32 (T032):   106.8
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Precipitation-Related Normals

Normal    Jan    Feb    Mar    Apr    May    Jun    Jul    Aug    Sep    Oct    Nov    Dec
Prcp:    2.34   2.85   3.87   4.36   5.16   3.88   3.68   2.96   3.22   3.65   4.21   3.22
Snow:     3.6    4.7    1.3    0.2    0.0    0.0    0.0    0.0    0.0    0.2    0.3    3.6

Number of Days
P001:     8.2    8.3   10.8   11.3   12.6   10.3    8.5    7.8    7.8    9.0   10.2   10.1
P010:     4.6    5.1    6.8    7.7    8.0    6.8    5.5    4.6    4.8    5.9    6.9    6.2
P100:     0.5    0.7    1.0    1.2    1.3    1.0    1.4    0.9    0.8    1.0    1.3    0.7
S001:     2.4    2.0    0.6    0.1    0.0    0.0    0.0    0.0    0.0    0.1    0.2    1.5
S010:     1.6    1.5    0.4    0.1    0.0    0.0    0.0    0.0    0.0    0.1    0.1    1.1
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
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Annual Values

Precipitation:   43.40 inches
     Snowfall:    13.9 inches

   Days precipitation at or above 0 inches (P000):   114.9
Days precipitation at or above 0.10 inches (P010):    72.9
Days Precipitation at or above 1.00 inches (P100):    11.8
      Days Snowfall at or above 0.1 inches (S001):     6.9
      Days Snowfall at or above 1.0 inches (S010):     4.9
     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