August weather forecast
Rock Valley, IA

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Weather in August

August, the last month of the summer in Rock Valley, is another warm month, with an average temperature ranging between min 60.3°F (15.7°C) and max 80.4°F (26.9°C).

Temperature

The transition from July to August brings an average high-temperature of a still moderately hot 80.4°F (26.9°C), barely different from July's 81.9°F (27.7°C). The average nighttime temperature in Rock Valley lowers to a mild 60.3°F (15.7°C) throughout August.

Humidity

The average relative humidity in August in Rock Valley is 76%.

Rainfall

In Rock Valley, during August, the rain falls for 13.8 days and regularly aggregates up to 2.4" (61mm) of precipitation. In Rock Valley, during the entire year, the rain falls for 130 days and collects up to 24.09" (612mm) of precipitation.

Snowfall

June through September are months without snowfall in Rock Valley.

Daylight

In Rock Valley, the average length of the day in August is 13h and 54min.
On the first day of August, sunrise is at 6:16 am and sunset at 8:46 pm. On the last day of the month, sunrise is at 6:49 am and sunset at 8:01 pm CDT.

Sunshine

In August, the average sunshine in Rock Valley is 9.9h.

UV index

The average daily maximum UV index in August is 5. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the ordinary person.
Note: The maximum UV index, 5 during August, leads to the following recommendations:
Make use of precautions - It is urged to ward off sun damage. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are August temperatures in Rock Valley?

An average high-temperature, in August, in Rock Valley, is 80.4°F (26.9°C) and the average low-temperature is 60.3°F (15.7°C). In July, the average heat index (a.k.a. 'apparent temperature', 'feels like'), which combines air temperature and relative humidity, is evaluated at 87.8°F (31°C).

What is the average humidity in August in Rock Valley?

In August, the average relative humidity in Rock Valley is 76%.

How many days does it rain in August in Rock Valley?

In August, in Rock Valley, Iowa, the rain falls for 13.8 days. Throughout August, 2.4" (61mm) of precipitation is accumulated.

When it does not snow in Rock Valley?

In Rock Valley, Iowa, snow does not fall in June through September.

What is the average length of the day in August in Rock Valley?

In Rock Valley, Iowa, the average day length in August is 13h and 54min.

What time are sunrise and sunset in August in Rock Valley?

In August, on the first day of the month, sunrise is at 6:16 am and sunset at 8:46 pm. On the last day of the month, sunrise is at 6:49 am and sunset at 8:01 pm CDT.

How long on average sun shines in August in Rock Valley?

In August, the average sunshine duration in Rock Valley is 9.9h.

What is the UV index reading in August in Rock Valley?

In Rock Valley, the average daily maximum UV index in August is 5. A UV Index of 3 to 5 symbolizes a moderate vulnerability 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
Rock Valley, IA

Average temperature in August - Rock Valley, IA
  • Average high temperature in August: 80.4°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 (24.1°F).

  • Average low temperature in August: 60.3°F

The month with the highest average low temperature is July (63.5°F).
The coldest month (with the lowest average low temperature) is January (10.8°F).

Average pressure in August
Rock Valley, IA

Average pressure in August - Rock Valley, IA
  • Average pressure in August: 29.94"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).

Average wind speed in August
Rock Valley, IA

Average wind speed in August - Rock Valley, IA
  • Average wind speed in August: 8mph

The windiest month (with the highest average wind speed) is April (11.2mph).
The calmest month (with the lowest average wind speed) is July (7.8mph).

Average humidity in August
Rock Valley, IA

Average humidity in August - Rock Valley, IA
  • Average humidity in August: 76%

The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is October (67%).

Average rainfall in August
Rock Valley, IA

Average rainfall in August - Rock Valley, IA
  • Average rainfall in August: 2.4"

The wettest month (with the highest rainfall) is June (3.78").
The driest month (with the least rainfall) is January (0.75").

Average rainfall days in August
Rock Valley, IA

Average rainfall days in August - Rock Valley, IA
  • Average rainfall days in August: 13.8 days

The month with the highest number of rainy days is June (18.8 days).
The month with the least rainy days is February (3.3 days).

Average snowfall in August
Rock Valley, IA

Average snowfall in August - Rock Valley, IA
  • Average snowfall in August: 0"

The month with the highest snowfall is February (4.49").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in August
Rock Valley, IA

Average snowfall days in August - Rock Valley, IA
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in August /
Average sunshine in August
Rock Valley, IA

Average daylight in August / Average sunshine in August - Rock Valley, IA
  • Average daylight in August: 13h and 5min

The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 0min).

  • Average sunshine in August: 9h and 5min

The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

Average sunshine days in August
Rock Valley, IA

Average sunshine days in August - Rock Valley, IA
  • Average sunshine days in August: 13.1 days

The month with the most sunshine days is November (19.7 days).
The month with the least sunshine days is June (8.3 days).

Average UV index in August
Rock Valley, IA

Average UV index in August - Rock Valley, IA
  • Average UV index in August: 5

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).

Average cloud cover in August
Rock Valley, IA

Average cloud cover in August - Rock Valley, IA
  • Average cloud cover in August: 29

The month with the most cloud cover is January (Cloud cover 55).
The month with the least cloud cover is July (Cloud cover 27).

Average visibility in August
Rock Valley, IA

Average visibility in August - Rock Valley, IA
  • Average visibility in August: 6mi

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

Rock Valley, Iowa, USA

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