August weather forecastDeKalb, IL
August
Weather in August
In August, weather in DeKalb, Illinois slightly cools down from the peak summer heat. There is a marginal decrease in both temperature extremes, paired with slightly less precipitation compared to July. The town enjoys sunny episodes, punctuated by occasional showers that lend a fresh breath to the surroundings. The slightly shorter daylight hours hint towards the upcoming descent into autumn. Therefore, August stands as a month of transition, subtly blending the summer effervescence with the calming touch of autumn.Temperature
As DeKalb transitions into August, the average high-temperature stands at a still moderately hot 78.4°F (25.8°C), offering little variation from the preceding month. In the month of August, DeKalb experiences an average low-temperature of 61.2°F (16.2°C).Humidity
In DeKalb, the average relative humidity in August is 84%.Rainfall
In DeKalb, in August, it is raining for 15.8 days, with typically 2.72" (69mm) of accumulated precipitation. Throughout the year, there are 152.6 rainfall days, and 32.09" (815mm) of precipitation is accumulated.Snowfall
In DeKalb, snow does not fall in June through September.Daylight
In DeKalb, the average length of the day in August is 13h and 49min.On the first day of August, sunrise is at 5:49 am and sunset at 8:13 pm. On the last day of the month, sunrise is at 6:20 am and sunset at 7:29 pm CDT.
Sunshine
The average sunshine in August is 9.5h.UV index
The months with the highest UV index are June and August, with an average maximum UV index of 6. A UV Index of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: The daily high UV index of 6 during August translates into the following recommendations:
Guard against overexposure. Protection from sun-induced harm is essential. During the period from 10 a.m. to 4 p.m., UV radiation is highest. Try to avoid direct sunlight during these hours. 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
Average temperature in August
DeKalb, IL
- Average high temperature in August: 78.4°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (27°F).
- Average low temperature in August: 61.2°F
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (15.1°F).
Average pressure in August
DeKalb, IL
- Average pressure in August: 29.98"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in August
DeKalb, IL
- Average wind speed in August: 6.2mph
The windiest month (with the highest average wind speed) is April (10mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in August
DeKalb, IL
- Average humidity in August: 84%
The months with the highest relative humidity are January and July (85%).
The months with the lowest relative humidity are April and October (75%).
Average rainfall in August
DeKalb, IL
- Average rainfall in August: 2.72"
The wettest month (with the highest rainfall) is May (4.37").
The driest month (with the least rainfall) is February (1.65").
Average rainfall days in August
DeKalb, IL
- Average rainfall days in August: 15.8 days
The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is February (4.7 days).
Average snowfall in August
DeKalb, IL
- Average snowfall in August: 0"
The month with the highest snowfall is January (5.55").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in August
DeKalb, IL
- Average snowfall days in August: 0 days
The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in August /
Average sunshine in August
DeKalb, IL
- Average daylight in August: 13h and 48min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in August: 9h and 30min
The month with the most sunshine is July (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in August
DeKalb, IL
- Average sunshine days in August: 12.9 days
The month with the most sunshine days is November (17.2 days).
The months with the least sunshine days are June and July (10.3 days).
Average UV index in August
DeKalb, IL
- Average UV index in August: 6
The months with the highest UV index are June and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in August
DeKalb, IL
- Average cloud cover in August: 35
The month with the most cloud cover is January (Cloud cover 63).
The months with the least cloud cover are August and September (Cloud cover 35).
Average visibility in August
DeKalb, IL
- Average visibility in August: 5mi
The months with the highest visibility are March, April, May, June, October, November and December (6mi).
The months with the lowest visibility are January, February, July, August and September (5mi).
