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
The shift into August in Decatur uncovers an average high-temperature of a still warm 81.1°F (27.3°C), subtly different from the previous month. During August nights, Decatur records an average temperature of 63.9°F (17.7°C).Heat index
The heat index in August is appraised at a hot 87.8°F (31°C). If one stays active during extended exposure, it might induce fatigue and result in heat cramps.Take into consideration that the heat index values are calculated for shade and light wind conditions. A rise in the heat index by 15 Fahrenheit (8 Celsius) degrees may result from direct sunlight exposure.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', gives a temperature feeling by integrating air temperature and humidity. Additional factors encompassing metabolic differences, the level of physical activity, and clothing can impact the individual's perception of temperature. Realize that direct exposure to sunlight can augment the felt heat, leading to a potential increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Young ones are generally at greater risk than adults due to their limited sweating ability. In addition, their large skin surface relative to their small bodies and higher heat production from their activities add to their vulnerability.
Humidity
The average relative humidity in August is 82%.Rainfall
In Decatur, in August, it is raining for 11.8 days, with typically 1.5" (38mm) of accumulated precipitation. In Decatur, during the entire year, the rain falls for 130.2 days and collects up to 16.34" (415mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In Decatur, the average length of the day in August is 13h and 41min.On the first day of August in Decatur, Illinois, sunrise is at 5:55 am and sunset at 8:08 pm. On the last day of the month, sunrise is at 6:23 am and sunset at 7:28 pm CDT.
Sunshine
In August, the average sunshine is 9.9h.UV index
The months with the highest UV index are June through August, with an average maximum UV index of 6. A UV Index estimate of 6 to 7 represents a high health hazard from exposure to the Sun's UV rays for the ordinary person.Note: A maximum high daily UV index of 6 during August translates into the following directions:
Skirt overexposure. People with light complexions might get scorched in under 20 minutes. Stay in the shade and limit sun exposure from 10 a.m. to 4 p.m., when UV radiation is most potent. Keep in mind that shade structures like parasols or canopies do not offer full protection. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are August temperatures in Decatur?
What is the average humidity in August in Decatur?
How much does it rain in Decatur in August?
When it does not snow in Decatur?
What is the average length of the day in August in Decatur?
When is the sunrise / sunset in August in Decatur?
How long on average sun shines in August in Decatur?
What are the months with the highest UV index in Decatur?
What is the UV index reading in August in Decatur?
Average temperature in August
Decatur, 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 (32.9°F).
- Average low temperature in August: 63.9°F
The month with the highest average low temperature is July (65.7°F).
The coldest month (with the lowest average low temperature) is January (21.2°F).
Average pressure in August
Decatur, 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 (29.92"Hg).
Average wind speed in August
Decatur, IL
- Average wind speed in August: 6.3mph
The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (6.3mph).
Average humidity in August
Decatur, IL
- Average humidity in August: 82%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (70%).
Average rainfall in August
Decatur, IL
- Average rainfall in August: 1.5"
The wettest month (with the highest rainfall) is May (2.01").
The driest months (with the least rainfall) are February and December (0.87").
Average rainfall days in August
Decatur, IL
- Average rainfall days in August: 11.8 days
The month with the highest number of rainy days is May (17 days).
The month with the least rainy days is February (5.8 days).
Average snowfall in August
Decatur, IL
- Average snowfall in August: 0"
The month with the highest snowfall is January (1.85").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in August
Decatur, IL
- Average snowfall days in August: 0 days
The month with the highest number of snowfall days is January (7.2 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in August /
Average sunshine in August
Decatur, IL
- Average daylight in August: 13h and 4min
The month with the longest days is June (Average daylight: 15h and 0min).
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 24min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in August
Decatur, IL
- Average sunshine days in August: 16.6 days
The month with the most sunshine days is October (19.8 days).
The month with the least sunshine days is May (11.5 days).
Average UV index in August
Decatur, IL
- Average UV index in August: 6
The months with the highest UV index are 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
Decatur, IL
- Average cloud cover in August: 31
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is September (Cloud cover 29).
Average visibility in August
Decatur, 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).
Decatur, Illinois, USA
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