August weather forecast
Lake Saint Louis, MO

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Weather in August

August, the last month of the summer in Lake Saint Louis, is another warm month, with an average temperature fluctuating between 66°F (18.9°C) and 85.5°F (29.7°C).

Temperature

Lake Saint Louis greets August with an average high-temperature of a moderately hot 85.5°F (29.7°C), marking a slight deviation from the preceding month. An average nighttime temperature of 66°F (18.9°C) is recorded during August.

Heat index

The heat index for August is calculated to be a torrid 96.8°F (36°C). Ensure extra safety steps, heat exhaustion and heat cramps are likely. Long activity might lead to heatstroke.
Be aware that heat index ratings are designed for shaded locations and minor breezes. Exposing to direct sunshine may enhance heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is a fusion of air temperature and moisture levels to demonstrate the sensation of heat. A person's impression of weather can be swayed by numerous aspects, among them metabolic variations, pregnancy, and activity levels. You should know that direct sun exposure can heighten weather effects, potentially elevating the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. Kids are generally in more danger than adults because they perspire less. Their large skin surface area compared to their small bodies and the excessive heat due to their actions raises their risk.
Sweat evaporation plays a crucial role in cooling the human body, a process enabled by perspiration. When there is abundant moisture in the air, the body's cooling through the evaporation process becomes less effective, leading to the sensation of overheating. The body is at risk of dehydration and related complications when it fails to shed excessive heat.

Humidity

The average relative humidity in August is 76%.

Rainfall

In Lake Saint Louis, in August, during 14.5 rainfall days, 3.07" (78mm) of precipitation is typically accumulated. Throughout the year, in Lake Saint Louis, there are 152.1 rainfall days, and 32.01" (813mm) of precipitation is accumulated.

Snowfall

May through October are months without snowfall in Lake Saint Louis.

Daylight

The average length of the day in August in Lake Saint Louis is 13h and 38min.
On the first day of August, sunrise is at 6:05 am and sunset at 8:13 pm. On the last day of the month, sunrise is at 6:32 am and sunset at 7:34 pm CDT.

Sunshine

The average sunshine in August in Lake Saint Louis is 10.3h.

UV index

The months with the highest UV index are May through August, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high threat to health from exposure to the Sun's UV rays for average individuals.
Note: The UV index of 6 during August translates into the following guidance:
Uphold preventive measures and conform to sun safety guidelines. Defending against skin and eye harm is crucial. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. Enhance your sun protection with tightly woven, yet airy clothing.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How hot is August in Lake Saint Louis?

Lake Saint Louis in August has an average high-temperature of 85.5°F (29.7°C) and an average low-temperature of 66°F (18.9°C). In August, the average heat index (a.k.a. 'feels like', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, is calculated to be 96.8°F (36°C).

What is the average humidity in August in Lake Saint Louis?

In August, the average relative humidity in Lake Saint Louis is 76%.

How much does it rain in Lake Saint Louis in August?

In Lake Saint Louis, Missouri, in August, during 14.5 rainfall days, 3.07" (78mm) of precipitation is typically accumulated.

When it does not snow in Lake Saint Louis?

In Lake Saint Louis, snow does not fall in May through October.

How many hours of daylight does Lake Saint Louis have in August?

The average day length in August in Lake Saint Louis is 13h and 38min.

When are sunrise and sunset in August in Lake Saint Louis?

In August, on the first day of the month, sunrise is at 6:05 am and sunset at 8:13 pm. On the last day of the month, in Lake Saint Louis, Missouri, sunrise is at 6:32 am and sunset at 7:34 pm CDT.

How long on average sun shines in August in Lake Saint Louis?

The average sunshine duration in August in Lake Saint Louis is 10.3h.

When is the highest UV index in Lake Saint Louis?

The months with the highest UV index in Lake Saint Louis, Missouri, are May through August, with an average maximum UV index of 6.

How high is the UV index in August in Lake Saint Louis?

The average daily maximum UV index in August in Lake Saint Louis, Missouri, is 6. A UV Index estimate of 6 to 7 represents a high hazard to health from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in August
Lake Saint Louis, MO

Average temperature in August - Lake Saint Louis, MO
  • Average high temperature in August: 85.5°F

The warmest month (with the highest average high temperature) is July (87.1°F).
The month with the lowest average high temperature is January (37.4°F).

  • Average low temperature in August: 66°F

The month with the highest average low temperature is July (68°F).
The coldest month (with the lowest average low temperature) is January (23.5°F).

Average pressure in August
Lake Saint Louis, MO

Average pressure in August - Lake Saint Louis, MO
  • Average pressure in August: 29.97"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in August
Lake Saint Louis, MO

Average wind speed in August - Lake Saint Louis, MO
  • Average wind speed in August: 5.5mph

The windiest months (with the highest average wind speed) are January and February (8.9mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).

Average humidity in August
Lake Saint Louis, MO

Average humidity in August - Lake Saint Louis, MO
  • Average humidity in August: 76%

The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (72%).

Average rainfall in August
Lake Saint Louis, MO

Average rainfall in August - Lake Saint Louis, MO
  • Average rainfall in August: 3.07"

The wettest month (with the highest rainfall) is April (3.82").
The driest month (with the least rainfall) is February (1.77").

Average rainfall days in August
Lake Saint Louis, MO

Average rainfall days in August - Lake Saint Louis, MO
  • Average rainfall days in August: 14.5 days

The month with the highest number of rainy days is May (17.2 days).
The month with the least rainy days is January (7.8 days).

Average snowfall in August
Lake Saint Louis, MO

Average snowfall in August - Lake Saint Louis, MO
  • Average snowfall in August: 0"

The month with the highest snowfall is February (3.15").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in August
Lake Saint Louis, MO

Average snowfall days in August - Lake Saint Louis, MO
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (7.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in August /
Average sunshine in August
Lake Saint Louis, MO

Average daylight in August / Average sunshine in August - Lake Saint Louis, MO
  • Average daylight in August: 13h and 4min

The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in August: 10h and 2min

The months with the most sunshine are June and July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).

Average sunshine days in August
Lake Saint Louis, MO

Average sunshine days in August - Lake Saint Louis, MO
  • Average sunshine days in August: 14.7 days

The month with the most sunshine days is October (18.6 days).
The month with the least sunshine days is June (10.9 days).

Average UV index in August
Lake Saint Louis, MO

Average UV index in August - Lake Saint Louis, MO
  • Average UV index in August: 6

The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in August
Lake Saint Louis, MO

Average cloud cover in August - Lake Saint Louis, MO
  • Average cloud cover in August: 27

The month with the most cloud cover is January (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in August
Lake Saint Louis, MO

Average visibility in August - Lake Saint Louis, MO
  • Average visibility in August: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Lake Saint Louis, Missouri, USA

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