Des Moines
Iowa, USA
Long-term weather forecast
Long-term weather forecast

August weather forecast and climate
Des Moines, IA

A close view of city buildings in Des Moines, Iowa
A close view of city buildings in Des Moines, Iowa
The last month of the summer, August, is also a moderately hot month in Des Moines, Iowa, with average temperature varying between 64.8°F (18.2°C) and 83.8°F (28.8°C).

Temperature

In August, the average high-temperature is almost the same as in July - a still warm 83.8°F (28.8°C). The average low-temperature, is 64.8°F (18.2°C).

Heat index

The average heat index is calculated to a hot 90.1°F (32.3°C). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature', 'apparent temperature', 'real feel', or 'feels like', combines air temperature and relative humidity to represent a human perceived temperature equivalent. This effect is subjective, depending on the activity and individual's heat perception influenced by various reasons (wind, differences in body mass, height, and shape, pregnancy). Be aware that direct exposure to sunlight increases heat impact, and may raise the heat index additionally, by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.

Humidity

The average relative humidity in Des Moines is 70%.

Rainfall

In Des Moines, Iowa, during August, the rain falls for 9.1 days and regularly aggregates up to 4.1" (104.9mm) of precipitation. Throughout the year, in Des Moines, there are 113.4 rainfall days, and 36" (914.9mm) of precipitation is accumulated.

Snowfall

May through September are months without snowfall.

Daylight

In August, the average length of the day in Des Moines is 13.8h.

Sunshine

In Des Moines, the average sunshine in August is 9.6h.

UV index

In Des Moines, the average daily maximum UV index in August is 8. A UV Index reading of 8 to 10 represents a very high threat to health from the exposure to the Sun's UV radiation for the average person.
Note: The average daily UV index of 8 in August transform into the following instructions:
Take special precautions, as unprotected eyes and skin can be burned and damaged quickly. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.

What is the temperature in August in Des Moines?

The average high-temperature, in August, in Des Moines, is 83.8°F (28.8°C), while the average low-temperature is 64.8°F (18.2°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), that factores the actual air temperature with the relative humidity, in August is estimated at 90.1°F (32.3°C).

What is the average humidity in August in Des Moines?

The average relative humidity in August in Des Moines is 70%.

How much does it rain in Des Moines in August?

In Des Moines, Iowa, in August, it is raining for 9.1 days, with typically 4.1" (104.9mm) of accumulated precipitation.

When it does not snow in Des Moines?

May through September are months without snowfall in Des Moines.

What is the average length of the day in August in Des Moines?

In August, the average length of the day in Des Moines, Iowa, is 13.8h.

How long on average sun shines in August in Des Moines?

The average sunshine in August in Des Moines is 9.6h.

How high is the UV index in August in Des Moines?

In August, the average daily maximum UV index is 8. A UV Index estimate of 8 to 10 represents a very high health vulnerability from unsafe exposure to the Sun's UV rays.
Average temperature in August - Des Moines, IA
  • Average high temperature in August: 83.8°F

The warmest month (with the highest average high temperature) is July (85.7°F).
The month with the lowest average high temperature is January (31°F).

  • Average low temperature in August: 64.8°F

The month with the highest average low temperature is July (66.8°F).
The coldest month (with the lowest average low temperature) is January (14.3°F).

Average humidity in August - Des Moines, IA
  • Average humidity in August: 70%

The month with the highest relative humidity is December (74.6%).
The month with the lowest relative humidity is May (63%).

Average rainfall in August - Des Moines, IA
  • Average rainfall in August: 4.1"

The wettest month (with the highest rainfall) is June (4.9").
The driest month (with the lowest rainfall) is January (1").

Average rainfall days in August - Des Moines, IA
  • Average rainfall days in August: 9.1 days

The month with the highest number of rainy days is May (12.5 days).
The month with the lowest number of rainy days is January (7.5 days).

Average snowfall in August - Des Moines, IA
  • Average snowfall in August: 0"

The month with the highest snowfall is December (9").
Months with the lowest snowfall are May, June, July, August and September (0").

Average snowfall days in August - Des Moines, IA
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (6.5 days).
Months with the lowest number of snowfall days are May, June, July, August and September (0 days).

Average daylight in August / Average sunshine in August - Des Moines, IA
  • Average daylight in August: 13.8h

The month with the longest days is June (Average daylight: 15.2h).
The month with shortest days is December (Average daylight: 9.2h).

  • Average sunshine in August: 9.6h

The month with most sunshine is July (Average sunshine: 10.9h).
The month with least sunshine is December (Average sunshine: 4.2h).

Average UV index in August - Des Moines, IA
  • Average UV index in August: 8

Months with the highest UV index are June and July (UV index 9).
Months with the lowest UV index are January and December (UV index 1).