O'Fallon (MO) monthly weather averages

Contents

Average daytime temperature

The bar chart below shows the average monthly peak daytime temperatures at O'Fallon

O'Fallon average temperature chart (Celsius) O'Fallon average temperature chart (Fahrenheit)
Average monthly temperatures in O'Fallon (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 2.7 5.4 12 18.9 23.9 28.7 31.3 30.2 26.2 20 12.3 5
°F 36.9 41.7 53.6 66 75 83.7 88.3 86.4 79.2 67.9 54.1 40.9

Please note: these are the average peak daytime temperatures (usually around mid-afternoon) so do not show daytime / night highs and lows. To see the daily range of temperatures have a look at the temperature max / min chart below.

Average rainfall & rainy days

The graph below shows the average rainfall and number of rainy days per month.

O'Fallon monthly rainfall chart (mm) O'Fallon monthly rainfall chart (inches)
Average monthly rainfall in O'Fallon (mm and inches)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm 43 49 85 96 106 95 92 78 88 71 78 67
inches 1.7 1.9 3.3 3.8 4.2 3.7 3.6 3.1 3.5 2.8 3.1 2.6
Rainy days 8 8 11 11 11 9 8 8 8 9 9 10

Average annual rainfall in O'Fallon: 895.5mm (352.6 inches)

Average daily sunshine

The bar chart below shows the average daily sunshine hours in O'Fallon

O'Fallon average daily sunshine chart
Average daily sunshine O'Fallon
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hrs sunshine 5.7 6.1 6.9 8 9.3 10.5 10.7 9.5 8.4 7.4 5.3 4.8

Day / night temperatures

The graph below shows the daily range of temperatures for each month.

O'Fallon average minimum / maximum temperatures (Celsius) O'Fallon average minimum / maximum temperatures (Fahrenheit)
Maximum and minimum daily temperatures in O'Fallon (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Min °C -7.6 -5.3 0.8 7.2 12.1 17.4 19.9 18.5 14.3 7.8 1.7 -4.6
Max °C 3 5.7 12.3 19.2 24.2 29 31.6 30.5 26.5 20.3 12.6 5.2
Min °F 18.3 22.6 33.4 45 53.7 63.3 67.7 65.3 57.7 46 35 23.7
Max °F 27.9 32.4 43.7 55.8 64.6 73.8 78.3 76.1 68.7 57.2 44.8 32.5

Sea temperature

The graph below shows the average sea temperature.

O'Fallon average sea temperature chart (Celsius) O'Fallon average sea temperature chart (Fahrenheit)
Average sea temperature around O'Fallon in degrees centigrade and fahrenheit
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 10.3 9.8 10.4 11.8 14 16.6 19.7 22.6 21.2 17.1 13.9 11.7
°F 50.5 49.7 50.7 53.2 57.1 61.9 67.5 72.7 70.2 62.8 56.9 53

Wind speed

The graph below shows the average wind speed.

O'Fallon average winspeed by month (km/h) O'Fallon average winspeed by month (mph)
Average wind speed in O'Fallon (mph and kmh)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
km/h 19 19 21 20 17 16 14 14 14 16 18 18
mph 12 12 13 12 10 10 9 9 9 10 11 11

A monthly average windspeed of over 16km/h or 10mph suggests a location is fairly windy.

Relative humidity

The graph below shows the average relative humidity.

O'Fallon relative humidity averages
Average relative humidity in O'Fallon
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
72% 72% 68% 64% 68% 68% 69% 71% 72% 69% 72% 75%

Other monthly averages

UV index Best time to go?

Beta

Current (hourly) weather 15 day forecast

O'Fallon weather stats

O'Fallon weather statistics
Hottest month: July 31.3°C 88.3°F
Driest month: January 43mm 1.7ins
Sunniest month: July 10.7hrs
Coldest month: January 2.7°C 36.9°F
Wettest month: May 106mm 4.2ins
Warmest sea: August 22.6°C 72.7°F
Map showing location of O'Fallon (38.81061, -90.69985) O'Fallon map pin © Google

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