St. Louis
Missouri, USA
Long-term weather forecast
Long-term weather forecast

August weather forecast and climate
St. Louis, MO

A beautiful twilight view of the Gateway Arch in St. Louis, Missouri, with a distant view of the city buildings mirrored in the waterfront
A beautiful twilight view of the Gateway Arch in St. Louis, Missouri, with a distant view of the city buildings mirrored in the waterfront
The last month of the summer, Agosto, is also a hot month in St. Louis, with average temperature ranging between max 88°F (31.1°C) and min 69.4°F (20.8°C).

Temperature

In St. Louis, Missouri, the average high-temperature in Agosto is almost the same as in Julio - a still hot 88°F (31.1°C). The average low-temperature, in Agosto, in St. Louis, is 69.4°F (20.8°C).

Heat index

In Agosto, the average heat index is appraised at a very hot 100.2°F (37.9°C). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature', 'felt air temperature', 'feels like', or 'real feel', is what the temperature feels like to the human body when the air temperature is combined with the relative humidity. Additional factors like pregnancy, metabolic differences, differences in body mass, height, and shape, and activity influence one's weather impression. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
The human body normally cools itself by perspiration. Excessive warmth is eliminated from the body by evaporation of sweat. High relative humidity reduces the evaporation rate, resulting in a lower heat removal rate from the body, causing the perception of being overheated. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.

Humidity

In Agosto, the average relative humidity in St. Louis, Missouri, is 70%.

Rainfall

In Agosto, in St. Louis, the rain falls for 8.2 days. Throughout Agosto, 2.99" (75.9mm) of precipitation is accumulated. Throughout the year, in St. Louis, there are 112.6 rainfall days, and 40.96" (1040.3mm) of precipitation is accumulated.

Snowfall

In St. Louis snow does not fall in Mayo through Octubre.

Daylight

In Agosto, the average length of the day in St. Louis is 13.6h.

Sunshine

The average sunshine in Agosto in St. Louis, Missouri, is 8.7h.

UV index

Junio through Agosto, with an average maximum UV index of 9, are months with the highest UV index in St. Louis. A UV Index of 8 to 10 symbolizes a very high threat to health from unprotected exposure to the Sun's UV rays for average individuals.
Note: The average daily UV index of 9 in Agosto transform into the following instructions:
Take special precautions, as unprotected eyes and skin can be burned and damaged quickly. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. A broad-spectrum sunscreen of SPF 30+ should be liberally applied and re-applied every two hours, and immediately after an outdoor workout or a swim.

What is the temperature in Agosto in St. Louis?

In Agosto, in St. Louis, the average high-temperature is 88°F (31.1°C), and the average low-temperature is 69.4°F (20.8°C). In Agosto, the average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), that combines air temperature and relative humidity, is estimated at 100.2°F (37.9°C).

What is the average humidity in Agosto in St. Louis?

The average relative humidity in Agosto in St. Louis, Missouri, is 70%.

How much does it rain in St. Louis in Agosto?

In St. Louis, Missouri, in Agosto, it is raining for 8.2 days, with typically 2.99" (75.9mm) of accumulated precipitation.

When it does not snow in St. Louis?

In St. Louis, Missouri, snow does not fall in Mayo through Octubre.

What is the average length of the day in Agosto in St. Louis?

The average length of the day in Agosto is 13.6h.

How long on average sun shines in Agosto in St. Louis?

In Agosto, the average sunshine in St. Louis, Missouri, is 8.7h.

When is the highest UV index in St. Louis?

Junio through Agosto, with an average maximum UV index of 9, are months with the highest UV index.

How high is the UV index in Agosto in St. Louis?

The average daily maximum UV index in Agosto is 9. A UV Index estimate of 8 to 10 represents a very high health threat from unprotected exposure to the UV radiation.
Average temperature in August - St. Louis, MO
  • Average high temperature in August: 87.9°F

The warmest month (with the highest average high temperature) is July (89.1°F).
The month with the lowest average high temperature is January (39.9°F).

  • Average low temperature in August: 69.4°F

The month with the highest average low temperature is July (71°F).
The coldest month (with the lowest average low temperature) is January (23.7°F).

Average humidity in August - St. Louis, MO
  • 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 - St. Louis, MO
  • Average rainfall in August: 3"

The wettest month (with the highest rainfall) is May (4.7").
The driest month (with the lowest rainfall) is February (2.2").

Average rainfall days in August - St. Louis, MO
  • 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 - St. Louis, MO
  • Average snowfall in August: 0"

The month with the highest snowfall is January (5.6").
Months with the lowest snowfall are May, June, July, August, September and October (0").

Average snowfall days in August - St. Louis, MO
  • 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 / Average sunshine in August - St. Louis, MO
  • 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 - St. Louis, MO
  • 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).