August weather forecast and climate
St. Louis, MO US

• 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).

• 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).

• 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%).

• 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).

• 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).

• 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).

• 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).

• Average daylight in August: 13.6h

The month with the longest days is June (Average daylight: 14.8h).
The month with shortest days is December (Average daylight: 9.5h).

• 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).

• 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).