August weather forecast
Grand River, IA

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Weather in August

August, the last month of the summer in Grand River, is also a moderately hot month, with temperature in the range of an average high of 81.9°F (27.7°C) and an average low of 63.5°F (17.5°C).

Temperature

Grand River's shift into August is marked by a subtle change to a still warm 81.9°F (27.7°C) from July's 83.5°F (28.6°C) in temperature. Grand River experiences an average low-temperature reading of 63.5°F (17.5°C) throughout August.

Heat index

August's average heat index is estimated at a tropical 87.8°F (31°C). Persistent activity under exposure might lead to a feeling of weariness, with subsequent heat cramps.
Observations indicate that the heat index values are for shady locations with light wind. The heat index has the potential to rise by 15 Fahrenheit (8 Celsius) degrees with direct sunshine exposure.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', blends air temperature and moisture content to represent the felt temperature to humans. One's weather perception can be influenced by a range of factors including metabolic differences, being pregnant, and their level of physical activity. Direct sun rays can make one feel hotter, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young children typically face greater hazards than adults because they do not sweat as much. Their larger skin surface in comparison to their little bodies and the high heat production from their active nature compounds their vulnerability.

Humidity

In August, the average relative humidity is 79%.

Rainfall

In August, in Grand River, the rain falls for 13.3 days. Throughout August, 1.93" (49mm) of precipitation is accumulated. Throughout the year, in Grand River, there are 132.4 rainfall days, and 20.24" (514mm) of precipitation is accumulated.

Snowfall

In Grand River, snow does not fall in June through September.

Daylight

In Grand River, the average length of the day in August is 13h and 45min.
On the first day of the month, sunrise is at 6:13 am and sunset at 8:31 pm. On the last day of August, sunrise is at 6:42 am and sunset at 7:49 pm CDT.

Sunshine

In Grand River, Iowa, the average sunshine in August is 10h.

UV index

The months with the highest UV index are June through August, with an average maximum UV index of 6. A UV Index value of 6 to 7 symbolizes a high health risk from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The daily high UV index of 6 during August translates into the following recommendations:
Continue precautions and advocate sun safety advice. Deterrence of sunburn is indispensable. During the period from 10 a.m. to 4 p.m., UV radiation is highest. Try to avoid direct sunlight during these hours. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
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Frequently asked questions

What is the average August temperature in Grand River?

The average high-temperature and low-temperature in Grand River during August are 81.9°F (27.7°C) and 63.5°F (17.5°C) respectively. The average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which combines air temperature and relative humidity, in August is estimated at 87.8°F (31°C).

What is the average humidity in August in Grand River?

In August, the average relative humidity in Grand River is 79%.

How much does it rain in Grand River in August?

In Grand River, Iowa, in August, during 13.3 rainfall days, 1.93" (49mm) of precipitation is typically accumulated.

When it does not snow in Grand River?

In Grand River, snow does not fall in June through September.

How many hours of daylight does Grand River have in August?

The average day length in August is 13h and 45min.

What time are sunrise and sunset in August in Grand River?

In August, on the first day of the month, sunrise is at 6:13 am and sunset at 8:31 pm. On the last day of the month, sunrise is at 6:42 am and sunset at 7:49 pm CDT.

How many hours of sunshine does Grand River have in August?

In Grand River, the average sunshine duration in August is 10h.

What is the month with the highest UV index in Grand River?

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

What is the UV index intensity in August in Grand River?

In Grand River, the average daily maximum UV index in August is 6. A UV Index reading of 6 to 7 represents a high health risk 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
Grand River, IA

Average temperature in August - Grand River, IA
  • Average high temperature in August: 81.9°F

The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is January (30.6°F).

  • Average low temperature in August: 63.5°F

The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (16.9°F).

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Average pressure in August
Grand River, IA

Average pressure in August - Grand River, IA
  • Average pressure in August: 29.96"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).

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Average wind speed in August
Grand River, IA

Average wind speed in August - Grand River, IA
  • Average wind speed in August: 6.9mph

The windiest months (with the highest average wind speed) are January, February and March (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.9mph).

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Average humidity in August
Grand River, IA

Average humidity in August - Grand River, IA
  • Average humidity in August: 79%

The month with the highest relative humidity is June (83%).
The month with the lowest relative humidity is October (72%).

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Average rainfall in August
Grand River, IA

Average rainfall in August - Grand River, IA
  • Average rainfall in August: 1.93"

The wettest month (with the highest rainfall) is June (3.43").
The driest months (with the least rainfall) are January and December (0.67").

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Average rainfall days in August
Grand River, IA

Average rainfall days in August - Grand River, IA
  • Average rainfall days in August: 13.3 days

The month with the highest number of rainy days is June (17.3 days).
The month with the least rainy days is January (4.8 days).

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Average snowfall in August
Grand River, IA

Average snowfall in August - Grand River, IA
  • Average snowfall in August: 0"

The month with the highest snowfall is January (2.72").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in August
Grand River, IA

Average snowfall days in August - Grand River, IA
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (8.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

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Average daylight in August /
Average sunshine in August
Grand River, IA

Average daylight in August / Average sunshine in August - Grand River, IA
  • Average daylight in August: 13h and 4min

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: 10h and 0min

The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).

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Average sunshine days in August
Grand River, IA

Average sunshine days in August - Grand River, IA
  • Average sunshine days in August: 13.8 days

The month with the most sunshine days is December (20.3 days).
The month with the least sunshine days is June (8.9 days).

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Average UV index in August
Grand River, IA

Average UV index in August - Grand River, IA
  • 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 January (UV index 1).

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Average cloud cover in August
Grand River, IA

Average cloud cover in August - Grand River, IA
  • Average cloud cover in August: 29

The month with the most cloud cover is January (Cloud cover 51).
The month with the least cloud cover is July (Cloud cover 28).

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Average visibility in August
Grand River, IA

Average visibility in August - Grand River, IA
  • Average visibility in August: 6mi

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

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Grand River, Iowa, USA

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