August weather forecastRock Falls, IL
August
Weather in August
August, the last month of the summer in Rock Falls, is also a moderately hot month, with an average temperature fluctuating between 79.3°F (26.3°C) and 61.7°F (16.5°C).Temperature
August brings an average high-temperature of a still moderately hot 79.3°F (26.3°C), nearly identical to the preceding month. Rock Falls usually reports an average low-temperature of 61.7°F (16.5°C) during the month of August.Humidity
In Rock Falls, the average relative humidity in August is 83%.Rainfall
In Rock Falls, in August, during 12.5 rainfall days, 1.34" (34mm) of precipitation is typically accumulated. Throughout the year, there are 130.2 rainfall days, and 17.36" (441mm) of precipitation is accumulated.Snowfall
In Rock Falls, snow does not fall in May through September.Daylight
The average length of the day in August is 13h and 49min.On the first day of August in Rock Falls, Illinois, sunrise is at 5:53 am and sunset at 8:16 pm. On the last day of the month, sunrise is at 6:24 am and sunset at 7:33 pm CDT.
Sunshine
In August, the average sunshine is 9.7h.UV index
In August, the average daily maximum UV index in Rock Falls is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 5 in August translates into these instructions:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. When the Sun is at its strongest around midday, find shade and limit exposure. During bright days, sunglasses that offer UVA and UVB defense are recommended.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in August
Rock Falls, IL
- Average high temperature in August: 79.3°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 (27.7°F).
- Average low temperature in August: 61.7°F
The month with the highest average low temperature is July (63.9°F).
The coldest month (with the lowest average low temperature) is January (14.9°F).
Average pressure in August
Rock Falls, IL
- Average pressure in August: 29.97"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in August
Rock Falls, IL
- Average wind speed in August: 6.4mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).
Average humidity in August
Rock Falls, IL
- Average humidity in August: 83%
The months with the highest relative humidity are January and July (85%).
The month with the lowest relative humidity is October (73%).
Average rainfall in August
Rock Falls, IL
- Average rainfall in August: 1.34"
The wettest month (with the highest rainfall) is May (2.83").
The driest months (with the least rainfall) are January and February (0.75").
Average rainfall days in August
Rock Falls, IL
- Average rainfall days in August: 12.5 days
The month with the highest number of rainy days is May (17.3 days).
The month with the least rainy days is January (4.8 days).
Average snowfall in August
Rock Falls, IL
- Average snowfall in August: 0"
The month with the highest snowfall is January (2.56").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in August
Rock Falls, IL
- Average snowfall days in August: 0 days
The month with the highest number of snowfall days is January (10.2 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
Rock Falls, 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 42min
The month with the most sunshine is July (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in August
Rock Falls, IL
- Average sunshine days in August: 15.8 days
The months with the most sunshine days are November and December (18.8 days).
The month with the least sunshine days is June (11.3 days).
Average UV index in August
Rock Falls, IL
- Average UV index in August: 5
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in August
Rock Falls, IL
- Average cloud cover in August: 32
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is September (Cloud cover 31).
Average visibility in August
Rock Falls, 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).
