August weather forecast
Saint Peters, MO

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Weather in August

August is a persistently warm and humid month for Saint Peters, Missouri. Although temperatures begin to dip from their peak, they remain high contributing to a noticeable summer heat. August stands out due to its uniquely high average temperature of 85.3°F (29.6°C) amidst a slow cooling trend. With the continued rainfall, humidity remains prevalent. The transition into September brings forth a welcome cool down accompanied by decreased rainfall.

Temperature

August's arrival brings an average high-temperature of a warm 85.3°F (29.6°C), slightly deviating from July's 87.1°F (30.6°C). Throughout August, Saint Peters experiences a low-temperature average of 66.4°F (19.1°C).

Heat index

During August, the heat index is calculated to be a fiery hot 95°F (35°C). Ensure extra safety measures, heat exhaustion and heat cramps are likely. Continuous activity might result in heatstroke.
Consider that heat index readings are for situations in the shade and light wind. Heat index values can rise by 15 Fahrenheit (8 Celsius) degrees when in direct sunlight.
Note: The heat index, also known as 'real feel' or 'apparent temperature', is what the temperature feels like to the human body when the air temperature is combined with the relative humidity. Additional factors encompassing metabolic differences, the level of physical activity, and clothing can impact the individual's perception of temperature. Consider the sun's direct rays and their impact; they can potentially increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for babies and toddlers. Children often fail to recognize the requirement to rest and rehydrate. Thirst, being a late symptom of dehydration, underlines the importance of maintaining hydration, especially during ongoing physical activities.
Sweat evaporation plays a crucial role in cooling the human body, a process enabled by perspiration. Under conditions of high relative humidity, the rate of evaporation decreases. This results in the body retaining more heat than under conditions of dry air. If heat absorption exceeds the body's cooling ability, body temperature can elevate, resulting in potential thermal illnesses.

Humidity

The average relative humidity in August is 75%.

Rainfall

In Saint Peters, during August, the rain falls for 12.6 days and regularly aggregates up to 2.4" (61mm) of precipitation. In Saint Peters, during the entire year, the rain falls for 133.4 days and collects up to 20.98" (533mm) of precipitation.

Snowfall

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

Daylight

In Saint Peters, the average length of the day in August is 13h and 38min.
On the first day of August, sunrise is at 6:04 am and sunset at 8:13 pm. On the last day of the month, sunrise is at 6:31 am and sunset at 7:33 pm CDT.

Sunshine

In Saint Peters, the average sunshine in August is 10.2h.

UV index

May through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index reading of 6 to 7 represents a high health hazard from unsafe exposure to UV radiation for ordinary individuals.
Note: In August, an average UV index of 6 transforms into the following instructions:
Persist with safeguards and heed sun safety doctrines. Keeping sunburn at bay is of prime importance. The Sun's UV radiation is at its strongest between the hours of 10 a.m. and 4 p.m. Minimize direct exposure to the sun during this period. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
Updated: Aug 16, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How hot is it in August?

The high-temperature, in August, in Saint Peters, is 85.3°F (29.6°C), while the low-temperature averages to 66.4°F (19.1°C). In August, the average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which factors the actual air temperature with the relative humidity, is calculated to be 95°F (35°C).

What is the average humidity in August?

In August, the average relative humidity in Saint Peters is 75%.

How many days does it rain in August?

In August, the rain falls for 12.6 days. Throughout August, 2.4" (61mm) of precipitation is accumulated.

When it does not snow?

April through October are months without snowfall.

What is the average length of the day in August?

In August, the average day length is 13h and 38min.

What time are sunrise and sunset in August?

In August, on the first day of the month, sunrise is at 6:04 am and sunset at 8:13 pm. On the last day of the month, sunrise is at 6:31 am and sunset at 7:33 pm CDT.

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

In August, the average sunshine duration is 10.2h.

When is the highest UV index?

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

What is the UV index intensity in August?

In Saint Peters, the average daily maximum UV index in August is 6. A UV Index of 6 to 7 symbolizes a high health vulnerability 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
Saint Peters, MO

Average temperature in August - Saint Peters, MO
  • Average high temperature in August: 85.3°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: 66.4°F

The month with the highest average low temperature is July (68.4°F).
The coldest month (with the lowest average low temperature) is January (23.9°F).

Average pressure in August
Saint Peters, MO

Average pressure in August - Saint Peters, 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 Peters, MO

Average wind speed in August - Saint Peters, MO
  • Average wind speed in August: 5.6mph

The windiest month (with the highest average wind speed) is January (9.1mph).
The calmest month (with the lowest average wind speed) is July (5.5mph).

Average humidity in August
Saint Peters, MO

Average humidity in August - Saint Peters, MO
  • Average humidity in August: 75%

The month with the highest relative humidity is May (78%).
The month with the lowest relative humidity is October (71%).

Average rainfall in August
Saint Peters, MO

Average rainfall in August - Saint Peters, MO
  • Average rainfall in August: 2.4"

The wettest month (with the highest rainfall) is April (2.48").
The driest month (with the least rainfall) is February (1.06").

Average rainfall days in August
Saint Peters, MO

Average rainfall days in August - Saint Peters, MO
  • Average rainfall days in August: 12.6 days

The month with the highest number of rainy days is May (15.6 days).
The month with the least rainy days is February (6.7 days).

Average snowfall in August
Saint Peters, MO

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

The month with the highest snowfall is February (1.65").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in August
Saint Peters, MO

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

The months with the highest number of snowfall days are January and February (5.8 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
Saint Peters, MO

Average daylight in August / Average sunshine in August - Saint Peters, 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 1min

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
Saint Peters, MO

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

The month with the most sunshine days is January (20.4 days).
The month with the least sunshine days is July (12.7 days).

Average UV index in August
Saint Peters, MO

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

Average cloud cover in August - Saint Peters, 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
Saint Peters, MO

Average visibility in August - Saint Peters, 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).

Saint Peters, Missouri, USA

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