August weather forecast and Climate
St. Louis, MO US

• The average high temperature in August: 31.1°C

The warmest month (with the highest average high temperature) is July (31.7°C).
The month with the lowest average high temperature is January (4.4°C).

• The average low temperature in August: 20.8°C

The month with the highest average low temperature is July (21.7°C).
The coldest month (with the lowest average low temperature) is January (-4.6°C).

• The average humidity in August: 70%

The month with the highest relative humidity is December (75.8%).
The month with the lowest relative humidity is April (63.5%).

• The average rainfall in August: 75.9mm

The wettest month (with the highest rainfall) is May (119.9mm).
The driest month (with the lowest rainfall) is February (56.9mm).

• The average rainfall days in August: 8.2 days

The month with the highest number of rainy days is May (11.9 days).
The month with the lowest number of rainy days is September (7.4 days).

• The average snowfall in August: 0mm

The month with the highest snowfall is January (142.2mm).
Months with the lowest snowfall are May, June, July, August, September and October (0mm).

• The average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (4.7 days).
Months with the lowest number of snowfall days are May, June, July, August, September and October (0 days).

• The average daylight in August: 14h

Months with the longest days are June and July (Average daylight: 15h).
Months with shortest days are January, November and December (Average daylight: 10h).

• The average sunshine in August: 8.7h

The month with most sunshine is July (Average sunshine: 10h).
The month with least sunshine is December (Average sunshine: 4.2h).

• The average UV index in August: 9

Months with the highest UV index are June, July and August (UV index 9).
Months with the lowest UV index are January and December (UV index 2).