August weather forecast
Rio, IL

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Weather in August

The last month of the summer, August, is another warm month in Rio, Illinois, with an average temperature fluctuating between 80.6°F (27°C) and 63.3°F (17.4°C).

Temperature

August ushers in an average high-temperature of a still moderately hot 80.6°F (27°C), aligning closely with the preceding month. During August, the nighttime temperature in Rio, Illinois, averages to a refreshing 63.3°F (17.4°C).

Heat index

For August, the heat index is estimated at a tropical 86°F (30°C). Long-standing exposure coupled with ongoing activity could result in exhaustion, possibly causing heat cramps.
Heat index values are typically calculated for conditions of shade and a light breeze. 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 'real feel' or 'felt air temperature', is a metric representing the sensation of warmth when air temperature and moisture come together. An individual's perception of weather can be affected by a variety of elements including metabolic differences, being pregnant, and their level of physical exertion. Considering the impact of direct sunlight, it's possible for the heat index to surge by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Children typically face more danger than adults as their sweat production is usually lower. Additionally, the bigger skin surface compared to their small size and the increased heat due to their activeness exacerbate the risk.

Humidity

In Rio, the average relative humidity in August is 81%.

Rainfall

In Rio, in August, during 10.1 rainfall days, 0.83" (21mm) of precipitation is typically accumulated. Throughout the year, in Rio, there are 109.9 rainfall days, and 11.14" (283mm) of precipitation is accumulated.

Snowfall

May through September are months without snowfall in Rio.

Daylight

In August, the average length of the day in Rio, Illinois, is 13h and 46min.
On the first day of the month, sunrise is at 5:58 am and sunset at 8:17 pm. On the last day of August, sunrise is at 6:27 am and sunset at 7:35 pm CDT.

Sunshine

In August, the average sunshine in Rio, Illinois, is 9.8h.

UV index

In Rio, the average daily maximum UV index in August is 5. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the average person.
Note: The UV index of 5 during August leads to these advisories:
Be vigilant - A duty to shield skin and eyes from injury exists. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Rio in August?

The high-temperature in Rio during August is 80.6°F (27°C) and the low-temperature is 63.3°F (17.4°C). In August, the average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which combines air temperature and relative humidity, is estimated at 86°F (30°C).

What is the average humidity in August in Rio?

In August, the average relative humidity in Rio, Illinois, is 81%.

How many days does it rain in August in Rio?

In Rio, Illinois, in August, it is raining for 10.1 days, with typically 0.83" (21mm) of accumulated precipitation.

When it does not snow in Rio?

May through September are months without snowfall.

What is the average length of the day in August in Rio?

The average day length in August in Rio, Illinois, is 13h and 46min.

When is the sunrise / sunset in August in Rio?

In August, on the first day of the month, sunrise is at 5:58 am and sunset at 8:17 pm. On the last day of the month, in Rio, Illinois, sunrise is at 6:27 am and sunset at 7:35 pm CDT.

How many hours of sunshine does Rio have in August?

The average sunshine duration in August in Rio, Illinois, is 9.8h.

What is the UV index intensity in August in Rio?

The average daily maximum UV index in August in Rio is 5. A UV Index estimate of 3 to 5 represents a moderate health threat from exposure to the Sun's UV radiation.
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
Rio, IL

Average temperature in August - Rio, IL
  • Average high temperature in August: 80.6°F

The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (29.5°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 (17.4°F).

Average pressure in August
Rio, IL

Average pressure in August - Rio, 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 (29.91"Hg).

Average wind speed in August
Rio, IL

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

The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).

Average humidity in August
Rio, IL

Average humidity in August - Rio, IL
  • Average humidity in August: 81%

The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (72%).

Average rainfall in August
Rio, IL

Average rainfall in August - Rio, IL
  • Average rainfall in August: 0.83"

The wettest month (with the highest rainfall) is May (1.65").
The driest months (with the least rainfall) are January and December (0.47").

Average rainfall days in August
Rio, IL

Average rainfall days in August - Rio, IL
  • Average rainfall days in August: 10.1 days

The month with the highest number of rainy days is May (15.2 days).
The month with the least rainy days is February (3.9 days).

Average snowfall in August
Rio, IL

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

The month with the highest snowfall is January (1.38").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in August
Rio, IL

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

The month with the highest number of snowfall days is January (8.8 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
Rio, IL

Average daylight in August / Average sunshine in August - Rio, 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 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 0min).

Average sunshine days in August
Rio, IL

Average sunshine days in August - Rio, IL
  • Average sunshine days in August: 16.8 days

The month with the most sunshine days is December (21.6 days).
The month with the least sunshine days is June (12.4 days).

Average UV index in August
Rio, IL

Average UV index in August - Rio, 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 December (UV index 1).

Average cloud cover in August
Rio, IL

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

The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is September (Cloud cover 30).

Average visibility in August
Rio, IL

Average visibility in August - Rio, 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).

Rio, Illinois, USA

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