August weather forecast
Iowa City, IA

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Golden and brown trees in a scenic, neat lawn near the mighty grandeur of the Old Capitol building, Iowa City
Golden and brown trees in a scenic, neat lawn near the mighty grandeur of the Old Capitol building, Iowa City

Weather in August

August witnesses a slight drop in temperature, though the weather continues to stay firmly within the summer category. Residents enjoy moderate balance between warmth and rainfall, thereby fostering enticing days for outdoor recreation. The long daylight hours provide ample viewing time for the city's attractions, complemented by less dense cloud coverage.

Temperature

With the onset of August, the average high-temperature registers at a still moderately hot 80.6°F (27°C), subtly different from July's 81.5°F (27.5°C). Iowa City experiences an average low-temperature of 62.2°F (16.8°C) in month of August.

Heat index

The heat index for August is estimated at a hot 86°F (30°C). When exposure and activity are sustained, they could induce fatigue, with a chance of heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Under direct sunshine, the heat index values might be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is the result of factoring in humidity to the air temperature, indicating perceived warmth. One's perception of temperature can vary depending on physical activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. 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 highly critical for babies and toddlers. Younglings are generally more in peril than adults due to their reduced perspiration. Coupled with a larger skin surface relative to their tiny bodies and greater heat production because of their activity, they become more at risk.

Humidity

The average relative humidity in August is 79%.

Rainfall

In Iowa City, in August, during 12.8 rainfall days, 1.93" (49mm) of precipitation is typically accumulated. In Iowa City, Iowa, during the entire year, the rain falls for 140.4 days and collects up to 29.57" (751mm) of precipitation.

Snowfall

In Iowa City, snow does not fall in May through September.

Daylight

In August, the average length of the day is 13h and 48min.
On the first day of the month, sunrise is at 6:01 am and sunset at 8:23 pm. On the last day of August, sunrise is at 6:31 am and sunset at 7:40 pm CDT.

Sunshine

In Iowa City, the average sunshine in August is 9.9h.

UV index

The average daily maximum UV index in August is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.
Note: In August, the maximum UV index of 5 translates into these guidelines:
Guard yourself - An obligation to protect skin and eyes from harm exists. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades.
Updated: Jul 15, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are August temperatures?

In August, the average high-temperature and low-temperature are 80.6°F (27°C) and 62.2°F (16.8°C) respectively. The average heat index (a.k.a. 'real feel', 'felt air temperature'), which combines air temperature and relative humidity, in August is estimated at 86°F (30°C).

What is the average humidity in August?

In August, the average relative humidity is 79%.

How many days does it rain in August in Iowa City?

In Iowa City, in August, it is raining for 12.8 days, with typically 1.93" (49mm) of accumulated precipitation.

When it does not snow?

May through September are months without snowfall.

How many hours of daylight does Iowa City have in August?

The average day length in August is 13h and 48min.

When is the sunrise / sunset in August?

On the first day of August, sunrise is at 6:01 am and sunset at 8:23 pm. On the last day of the month, sunrise is at 6:31 am and sunset at 7:40 pm CDT.

How long on average sun shines in August?

The average sunshine duration in August is 9.9h.

What is the UV index intensity in August?

In August, the average daily maximum UV index 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
Iowa City, IA

Average temperature in August - Iowa City, IA
  • Average high temperature in August: 80.6°F

The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (27.3°F).

  • Average low temperature in August: 62.2°F

The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (15.3°F).

Average pressure in August
Iowa City, IA

Average pressure in August - Iowa City, IA
  • 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
Iowa City, IA

Average wind speed in August - Iowa City, IA
  • Average wind speed in August: 6.9mph

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 (6.9mph).

Average humidity in August
Iowa City, IA

Average humidity in August - Iowa City, IA
  • Average humidity in August: 79%

The months with the highest relative humidity are January and July (83%).
The month with the lowest relative humidity is October (72%).

Average rainfall in August
Iowa City, IA

Average rainfall in August - Iowa City, IA
  • Average rainfall in August: 1.93"

The wettest month (with the highest rainfall) is May (4.69").
The driest months (with the least rainfall) are January and February (1.34").

Average rainfall days in August
Iowa City, IA

Average rainfall days in August - Iowa City, IA
  • Average rainfall days in August: 12.8 days

The month with the highest number of rainy days is May (18.4 days).
The month with the least rainy days is February (5 days).

Average snowfall in August
Iowa City, IA

Average snowfall in August - Iowa City, IA
  • Average snowfall in August: 0"

The month with the highest snowfall is January (5.28").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in August
Iowa City, IA

Average snowfall days in August - Iowa City, IA
  • 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
Iowa City, IA

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

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

  • Average sunshine in August: 9h and 5min

The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).

Average sunshine days in August
Iowa City, IA

Average sunshine days in August - Iowa City, IA
  • Average sunshine days in August: 15.8 days

The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is May (10 days).

Average UV index in August
Iowa City, IA

Average UV index in August - Iowa City, IA
  • 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
Iowa City, IA

Average cloud cover in August - Iowa City, IA
  • Average cloud cover in August: 29

The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 29).

Average visibility in August
Iowa City, IA

Average visibility in August - Iowa City, IA
  • 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).

Iowa City, Iowa, USA

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