August weather forecast
Saint Clair, MO

Share

Weather in August

August, the last month of the summer in Saint Clair, is another hot month, with temperature in the range of an average low of 65.8°F (18.8°C) and an average high of 87.3°F (30.7°C).

Temperature

The commencement of August notes an average high-temperature of a still hot 87.3°F (30.7°C), exhibiting little difference from the previous month. During the month of August, the temperature generally drops to a low average of 65.8°F (18.8°C).

Heat index

Throughout August, the heat index is calculated to be a torrid 100.4°F (38°C). Undertake special precautions, the probability of heat exhaustion and heat cramps is high. Prolonged activity may provoke heatstroke.
Evaluating the heat index requires understanding its values in the shade and with gentle winds. Uninterrupted exposure to the sun may boost the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', gives an indication of how one might feel in terms of heat after considering humidity. The influence of weather can be personal, changing with an individual's body mass, height, and level of physical exertion. Direct sun exposure is noteworthy in its ability to escalate the felt temperature, potentially adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are particularly relevant to babies and toddlers. Children commonly overlook the importance of rest and fluid replenishment. Thirst, being a delayed sign of dehydration, emphasizes the need to keep hydration up, especially during lengthy physical activities.
The physiological way the human body responds to excessive heat is by inducing perspiration, using sweat evaporation as a cooling mechanism. 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. When body temperature rises due to an imbalance in heat gain, there's a potential for dehydration and overheating.

Humidity

In Saint Clair, the average relative humidity in August is 74%.

Rainfall

In August, the rain falls for 13.8 days. Throughout August, 2.44" (62mm) of precipitation is accumulated. Throughout the year, there are 126.7 rainfall days, and 20.63" (524mm) of precipitation is accumulated.

Snowfall

In Saint Clair, snow does not fall in April through October.

Daylight

In Saint Clair, the average length of the day in August is 13h and 37min.
On the first day of the month, sunrise is at 6:06 am and sunset at 8:13 pm. On the last day of August, sunrise is at 6:33 am and sunset at 7:34 pm CDT.

Sunshine

In August, the average sunshine is 10h.

UV index

May through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index value of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV radiation for average individuals.
Note: The maximum daily UV index of 6 in August converts into the following recommendations:
Guard oneself from overexposure. Defence against sun injury is vital. Stay in the shade and avoid direct Sun exposure from 10 a.m. to 4 p.m., a period when UV radiation is particularly strong, noting that parasols or canopies may not offer total sun protection. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades.
Updated: Jul 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How hot is it in Saint Clair in August?

Saint Clair in August has an average high-temperature of 87.3°F (30.7°C) and an average low-temperature of 65.8°F (18.8°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which factors the actual air temperature with the relative humidity, in August is calculated to be 100.4°F (38°C).

What is the average humidity in August?

In Saint Clair, the average relative humidity in August is 74%.

How much does it rain in August?

In Saint Clair, during August, the rain falls for 13.8 days and regularly aggregates up to 2.44" (62mm) of precipitation.

When it does not snow?

April through October are months without snowfall.

What is the average length of the day in August?

In Saint Clair, the average day length in August is 13h and 37min.

What time are sunrise and sunset in August?

In August, on the first day of the month, sunrise is at 6:06 am and sunset at 8:13 pm. On the last day of the month, in Saint Clair, sunrise is at 6:33 am and sunset at 7:34 pm CDT.

How many hours of sunshine does Saint Clair have in August?

In August, the average sunshine duration is 10h.

What are the months with the highest UV index?

The months with the highest UV index are May through August, with an average maximum UV index of 6.

How high is the UV index in August?

In Saint Clair, the average daily maximum UV index in August is 6. A UV Index reading of 6 to 7 represents a high health vulnerability from exposure to Sun's UV rays.
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
Saint Clair, MO

Average temperature in August - Saint Clair, MO
  • Average high temperature in August: 87.3°F

The warmest month (with the highest average high temperature) is July (88.9°F).
The month with the lowest average high temperature is January (39°F).

  • Average low temperature in August: 65.8°F

The month with the highest average low temperature is July (68°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).

Average pressure in August
Saint Clair, MO

Average pressure in August - Saint Clair, 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
Saint Clair, MO

Average wind speed in August - Saint Clair, MO
  • Average wind speed in August: 5.3mph

The windiest month (with the highest average wind speed) is January (8.5mph).
The calmest months (with the lowest average wind speed) are July and August (5.3mph).

Average humidity in August
Saint Clair, MO

Average humidity in August - Saint Clair, MO
  • Average humidity in August: 74%

The month with the highest relative humidity is May (78%).
The month with the lowest relative humidity is October (72%).

Average rainfall in August
Saint Clair, MO

Average rainfall in August - Saint Clair, MO
  • Average rainfall in August: 2.44"

The wettest months (with the highest rainfall) are April and May (2.48").
The driest months (with the least rainfall) are January and February (0.98").

Average rainfall days in August
Saint Clair, MO

Average rainfall days in August - Saint Clair, MO
  • Average rainfall days in August: 13.8 days

The month with the highest number of rainy days is May (15.4 days).
The month with the least rainy days is January (5.9 days).

Average snowfall in August
Saint Clair, MO

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

The month with the highest snowfall is February (1.57").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in August
Saint Clair, MO

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

The month with the highest number of snowfall days is January (6.2 days).
The months with the least snowfall days are May, June, July and August (0 days).

Average daylight in August /
Average sunshine in August
Saint Clair, MO

Average daylight in August / Average sunshine in August - Saint Clair, 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 0min

The months with the most sunshine are June and July (Average sunshine: 10h and 24min).
The months with the least sunshine are January and February (Average sunshine: 4h and 42min).

Average sunshine days in August
Saint Clair, MO

Average sunshine days in August - Saint Clair, MO
  • Average sunshine days in August: 15.2 days

The month with the most sunshine days is January (20.6 days).
The month with the least sunshine days is May (13.7 days).

Average UV index in August
Saint Clair, MO

Average UV index in August - Saint Clair, 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
Saint Clair, MO

Average cloud cover in August - Saint Clair, MO
  • Average cloud cover in August: 30

The months with the most cloud cover are January and February (Cloud cover 49).
The months with the least cloud cover are June and July (Cloud cover 29).

Average visibility in August
Saint Clair, MO

Average visibility in August - Saint Clair, MO
  • Average visibility in August: 5mi

The months with the highest visibility are January, February, March, April, June, July, October, November and December (6mi).
The months with the lowest visibility are May, August and September (5mi).

Saint Clair, Missouri, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location