August weather forecast
Romeoville, IL

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Weather in August

The last month of the summer, August, is also a moderately hot month in Romeoville, Illinois, with temperature in the range of an average high of 80.2°F (26.8°C) and an average low of 63.9°F (17.7°C).

Temperature

The advent of August brings an average high-temperature of a still warm 80.2°F (26.8°C), exhibiting minor difference from the previous month. Romeoville temperatures generally rest at a low of 63.9°F (17.7°C) during the August nights.

Humidity

The average relative humidity in August is 78%.

Rainfall

In Romeoville, Illinois, in August, it is raining for 16.3 days, with typically 2.48" (63mm) of accumulated precipitation. Throughout the year, there are 145.4 rainfall days, and 22.83" (580mm) of precipitation is accumulated.

Snowfall

In Romeoville, snow does not fall in June through September.

Daylight

In August, the average length of the day is 13h and 48min.
On the first day of August, sunrise is at 5:47 am and sunset at 8:09 pm. On the last day of the month, sunrise is at 6:18 am and sunset at 7:26 pm CDT.

Sunshine

July and August, with an average of 9.9h of sunshine, are months with the most sunshine.

UV index

June through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high health hazard from exposure to the Sun's UV radiation for ordinary individuals.
Note: The maximum daily UV index, 6 in August, converts into the following recommendations:
Guard against overexposure. Protection from sun-induced harm is essential. Be aware that the sun's UV radiation is strongest between 10 a.m. and 4 p.m. and try to reduce direct sun exposure during this period as much as possible. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades.
Updated: Aug 15, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in August?

In August, in Romeoville, the average high-temperature is 80.2°F (26.8°C), and the average low-temperature is 63.9°F (17.7°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), which factors the actual air temperature with the relative humidity, in July is computed to be 87.8°F (31°C).

What is the average humidity in August?

In Romeoville, the average relative humidity in August is 78%.

How much does it rain in August?

In August, the rain falls for 16.3 days. Throughout August, 2.48" (63mm) of precipitation is accumulated.

When it does not snow?

June through September are months without snowfall.

What is the average length of the day in August?

In Romeoville, the average day length in August is 13h and 48min.

When are sunrise and sunset in August?

On the first day of August, sunrise is at 5:47 am and sunset at 8:09 pm. On the last day of the month, sunrise is at 6:18 am and sunset at 7:26 pm CDT.

What is the month with the most sunshine in Romeoville?

The months with the most sunshine are July and August, with an average of 9.9h of sunshine.

How many hours of sunshine does Romeoville have in August?

In August, the average sunshine duration is 9.9h.

When is the highest UV index?

The months with the highest UV index in Romeoville are June through August, with an average maximum UV index of 6.

How high is the UV index in August?

In Romeoville, the average daily maximum UV index in August is 6. A UV Index of 6 to 7 symbolizes a high health risk from 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
Romeoville, IL

Average temperature in August - Romeoville, IL
  • Average high temperature in August: 80.2°F

The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (28.8°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 (17.1°F).

Average pressure in August
Romeoville, IL

Average pressure in August - Romeoville, 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
Romeoville, IL

Average wind speed in August - Romeoville, IL
  • Average wind speed in August: 6mph

The windiest month (with the highest average wind speed) is January (9.7mph).
The calmest month (with the lowest average wind speed) is August (6mph).

Average humidity in August
Romeoville, IL

Average humidity in August - Romeoville, IL
  • Average humidity in August: 78%

The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (73%).

Average rainfall in August
Romeoville, IL

Average rainfall in August - Romeoville, IL
  • Average rainfall in August: 2.48"

The wettest month (with the highest rainfall) is May (2.83").
The driest month (with the least rainfall) is December (1.06").

Average rainfall days in August
Romeoville, IL

Average rainfall days in August - Romeoville, IL
  • Average rainfall days in August: 16.3 days

The month with the highest number of rainy days is July (18.1 days).
The month with the least rainy days is February (4.9 days).

Average snowfall in August
Romeoville, IL

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

The month with the highest snowfall is January (3.11").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in August
Romeoville, IL

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

The month with the highest number of snowfall days is January (12.1 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in August /
Average sunshine in August
Romeoville, IL

Average daylight in August / Average sunshine in August - Romeoville, IL
  • Average daylight in August: 13h and 5min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).

  • Average sunshine in August: 9h and 5min

The months with the most sunshine are July and August (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).

Average sunshine days in August
Romeoville, IL

Average sunshine days in August - Romeoville, IL
  • Average sunshine days in August: 10.8 days

The month with the most sunshine days is November (18.4 days).
The month with the least sunshine days is July (9.3 days).

Average UV index in August
Romeoville, IL

Average UV index in August - Romeoville, 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
Romeoville, IL

Average cloud cover in August - Romeoville, IL
  • Average cloud cover in August: 31

The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 31).

Average visibility in August
Romeoville, IL

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

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

Romeoville, Illinois, USA

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