Contents
- Weather in August
- Frequently asked questions
- Average temperature in August
- Average pressure in August
- Average wind speed in August
- Average humidity in August
- Average rainfall in August
- Average rainfall days in August
- Average snowfall in August
- Average snowfall days in August
- Average daylight in August
- Average sunshine in August
- Average sunshine days in August
- Average UV index in August
- Average cloud cover in August
- Average visibility in August
Weather in August
Temperature
A minimal variation is noted in Charleston's average high-temperature at the onset of August, reaching a still warm 81.1°F (27.3°C) from July's 82°F (27.8°C). Charleston in August anticipates an average nighttime temperature of 64°F (17.8°C).Heat index
August's mean heat index is evaluated at a hot 87.8°F (31°C). Exhaustion is likely with prolonged exposure and activity. Sustaining activity may result in heat cramps.Heat index readings emphasize conditions of light breezes and shaded spots. Direct sunshine exposure could raise heat index values by as much as 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', embodies the combination of air temperature and moisture content to illustrate perceived heat. The individual's temperature perception can be influenced by numerous factors such as metabolic variations, physical activity, and clothing. In direct sunlight, the heat's impact can be heightened, potentially leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Young children are more at risk than adults since they tend to sweat less. Moreover, their large skin surface in proportion to their small bodies and the high heat production due to their activities contribute to their vulnerability.
Humidity
In August, the average relative humidity is 82%.Rainfall
In Charleston, during August, the rain falls for 14.3 days and regularly aggregates up to 2.28" (58mm) of precipitation. Throughout the year, there are 148 rainfall days, and 25.63" (651mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
In Charleston, the average length of the day in August is 13h and 40min.On the first day of the month, sunrise is at 5:53 am and sunset at 8:04 pm. On the last day of August, sunrise is at 6:20 am and sunset at 7:24 pm CDT.
Sunshine
In Charleston, the average sunshine in August is 9.8h.UV index
The months with the highest UV index in Charleston are June through August, with an average maximum UV index of 6. A UV Index value of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for average individuals.Note: The UV index of 6 during August leads to these advisories:
Incorporate safeguards and honour sun safety principles. Protection from skin and eye damage is obligatory. From 10 a.m. to 4 p.m., when UV radiation is at its strongest, limit direct exposure to the Sun and note that shade structures may not provide full sun protection. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are August temperatures?
What is the average humidity in August?
How many days does it rain in August?
When it does not snow?
What is the average length of the day in August?
When are sunrise and sunset in August?
How long on average sun shines in August?
What is the month with the highest UV index?
How high is the UV index in August?
Average temperature in August
Charleston, IL
- Average high temperature in August: 81.1°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (34°F).
- Average low temperature in August: 64°F
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (21.9°F).
Average pressure in August
Charleston, IL
- Average pressure in August: 29.98"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in August
Charleston, IL
- Average wind speed in August: 6.3mph
The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest month (with the lowest average wind speed) is July (6.2mph).
Average humidity in August
Charleston, IL
- Average humidity in August: 82%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (70%).
Average rainfall in August
Charleston, IL
- Average rainfall in August: 2.28"
The wettest month (with the highest rainfall) is April (3.31").
The driest month (with the least rainfall) is February (1.3").
Average rainfall days in August
Charleston, IL
- Average rainfall days in August: 14.3 days
The month with the highest number of rainy days is May (16.8 days).
The month with the least rainy days is February (7.8 days).
Average snowfall in August
Charleston, IL
- Average snowfall in August: 0"
The month with the highest snowfall is December (2.13").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in August
Charleston, IL
- Average snowfall days in August: 0 days
The month with the highest number of snowfall days is January (8.1 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
Charleston, IL
- Average daylight in August: 13h and 4min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in August: 9h and 5min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in August
Charleston, IL
- Average sunshine days in August: 12.7 days
The month with the most sunshine days is October (18.3 days).
The month with the least sunshine days is July (10.6 days).
Average UV index in August
Charleston, IL
- Average UV index in August: 6
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in August
Charleston, IL
- Average cloud cover in August: 32
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is June (Cloud cover 31).
Average visibility in August
Charleston, IL
- Average visibility in August: 5mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
Charleston, Illinois, USA
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