August weather forecast
Roseville, IL

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Weather in August

The last month of the summer, August, is also a moderately hot month in Roseville, Illinois, with an average temperature varying between 81.1°F (27.3°C) and 63.3°F (17.4°C).

Temperature

As July transitions into August, the average high-temperature rests at a still warm 81.1°F (27.3°C), maintaining a close resemblance to the previous month. Nighttime temperatures in August average to an enjoyable 63.3°F (17.4°C).

Heat index

The average heat index in August is computed to be a hot 86°F (30°C). Enduring exposure and continuous activity might cause a feeling of tiredness and induce heat cramps.
When assessing, remember that heat index measurements are for light winds and shaded spots. If exposed to direct sunlight, the heat index could climb by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', arises from combining readings of air temperature and relative moisture content. The individual's experience of temperature can be shaped by numerous aspects such as metabolic variations, physical exertion, and attire. The sun, when shining directly, can have a significant impact on the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Youngsters frequently overlook the need for breaks and fluid intake. Thirst is an advanced sign of dehydration - thereby highlighting the importance of keeping hydrated, particularly during long physical activities.

Humidity

The average relative humidity in August is 80%.

Rainfall

In August, the rain falls for 14 days. Throughout August, 2.13" (54mm) of precipitation is accumulated. In Roseville, during the entire year, the rain falls for 149.4 days and collects up to 30.16" (766mm) of precipitation.

Snowfall

In Roseville, snow does not fall in May through September.

Daylight

The average length of the day in August is 13h and 44min.
On the first day of August, sunrise is at 6:00 am and sunset at 8:17 pm. On the last day of the month, sunrise is at 6:29 am and sunset at 7:36 pm CDT.

Sunshine

In Roseville, the average sunshine in August is 9.8h.

UV index

In Roseville, the average daily maximum UV index in August is 5. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: In August, the maximum UV index of 5 suggests these recommendations:
Make use of precautions - Shielding skin and eyes from injury is a requirement. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days.
Updated: Aug 30, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average August temperature?

In August, the average high-temperature and low-temperature are 81.1°F (27.3°C) and 63.3°F (17.4°C) respectively. In August, the average heat index (a.k.a. 'feels like', 'apparent temperature'), which represents the influence of relative humidity on air temperature, is computed to be 86°F (30°C).

What is the average humidity in August?

In August, the average relative humidity is 80%.

How many days does it rain in August?

In Roseville, Illinois, in August, it is raining for 14 days, with typically 2.13" (54mm) of accumulated precipitation.

When it does not snow?

May through September are months without snowfall.

What is the average length of the day in August?

In August, the average day length is 13h and 44min.

When is the sunrise / sunset in August?

On the first day of August in Roseville, sunrise is at 6:00 am and sunset at 8:17 pm. On the last day of the month, sunrise is at 6:29 am and sunset at 7:36 pm CDT.

How long on average sun shines in August in Roseville?

In Roseville, the average sunshine duration in August is 9.8h.

How high is the UV index in August?

In Roseville, the average daily maximum UV index in August is 5. A UV Index value of 3 to 5 symbolizes a medium hazard to health from unsafe exposure to Sun's UV rays.
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
Roseville, IL

Average temperature in August - Roseville, 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 (29.7°F).

  • Average low temperature in August: 63.3°F

The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (17.6°F).

Average pressure in August
Roseville, IL

Average pressure in August - Roseville, IL
  • Average pressure in August: 29.97"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in August
Roseville, IL

Average wind speed in August - Roseville, IL
  • Average wind speed in August: 6.8mph

The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).

Average humidity in August
Roseville, IL

Average humidity in August - Roseville, IL
  • Average humidity in August: 80%

The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (71%).

Average rainfall in August
Roseville, IL

Average rainfall in August - Roseville, IL
  • Average rainfall in August: 2.13"

The wettest month (with the highest rainfall) is May (4.25").
The driest month (with the least rainfall) is January (1.46").

Average rainfall days in August
Roseville, IL

Average rainfall days in August - Roseville, IL
  • Average rainfall days in August: 14 days

The month with the highest number of rainy days is May (19 days).
The month with the least rainy days is February (5.8 days).

Average snowfall in August
Roseville, IL

Average snowfall in August - Roseville, IL
  • Average snowfall in August: 0"

The month with the highest snowfall is January (4.61").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in August
Roseville, IL

Average snowfall days in August - Roseville, IL
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (10.9 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
Roseville, IL

Average daylight in August / Average sunshine in August - Roseville, 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 18min).

  • Average sunshine in August: 9h and 5min

The month with the most sunshine is June (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

Average sunshine days in August
Roseville, IL

Average sunshine days in August - Roseville, IL
  • Average sunshine days in August: 13.8 days

The month with the most sunshine days is November (18 days).
The month with the least sunshine days is June (9.2 days).

Average UV index in August
Roseville, IL

Average UV index in August - Roseville, IL
  • Average UV index in August: 5

The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).

Average cloud cover in August
Roseville, IL

Average cloud cover in August - Roseville, IL
  • Average cloud cover in August: 30

The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are August and September (Cloud cover 30).

Average visibility in August
Roseville, IL

Average visibility in August - Roseville, IL
  • Average visibility in August: 6mi

The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).

Roseville, Illinois, USA

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