August weather forecast
Ottumwa, IA

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Weather in August

August maintains the warm spell in Ottumwa with the warmest days reaching around 81.7°F (27.6°C). Compared to July, August tends to bring about slightly reduced temperatures and relative humidity. This does not take away from the joy of summer as the city continues to bask in around 13.8 daylight hours. The rainfall and wind speed take a middling stance between the summer drought and the impending autumn showers. The last of the summer break, August, spends its days with residents soaking up the sun before the transition into autumn.

Temperature

August's advent denotes a minor fluctuation in the average high-temperature to a still moderately hot 81.7°F (27.6°C) from July's 82.6°F (28.1°C). August brings an average low-temperature of 63.1°F (17.3°C) to Ottumwa.

Heat index

Throughout August, the heat index is computed to be a hot 87.8°F (31°C). Persisting in activity during long-term exposure might induce weariness, with subsequent heat cramps.
Note that heat index values are valued for light wind and location in the shade. The heat index has the possibility to be enhanced by 15 Fahrenheit (8 Celsius) degrees when there is direct sun exposure.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is a value derived by merging air temperature with the humidity to convey how the climate feels. This effect tends to be personal, with the weather perception differing among individuals due to variations in body mass, height, and exertion. Should you be directly under the sun, anticipate a possible increase in the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. Youngsters often neglect the necessity for rest and hydration. Thirst is a sign of advancing dehydration - thus the importance of maintaining hydration, specifically during long-lasting physical activities.

Humidity

In Ottumwa, Iowa, the average relative humidity in August is 78%.

Rainfall

In Ottumwa, during August, the rain falls for 11.8 days and regularly aggregates up to 2.2" (56mm) of precipitation. In Ottumwa, during the entire year, the rain falls for 134.5 days and collects up to 27.17" (690mm) of precipitation.

Snowfall

In Ottumwa, snow does not fall in June through September.

Daylight

The average length of the day in August is 13h and 46min.
On the first day of the month, sunrise is at 6:06 am and sunset at 8:25 pm. On the last day of August, in Ottumwa, sunrise is at 6:36 am and sunset at 7:43 pm CDT.

Sunshine

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

UV index

June through August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high threat to health from unsafe exposure to UV radiation for the ordinary person.
Note: A maximum high daily UV index of 6 during August translates into the following directions:
Undertake precautions and comply with sun safety standards. Protection from skin and eye injury is vital. UV radiation from the sun is at its strongest between 10 a.m. and 4 p.m. Try to limit direct exposure during these hours. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average August temperature in Ottumwa?

The high-temperature, in August, in Ottumwa, is 81.7°F (27.6°C), while the low-temperature averages to 63.1°F (17.3°C). In August, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, is computed to be 87.8°F (31°C).

What is the average humidity in August in Ottumwa?

In Ottumwa, the average relative humidity in August is 78%.

How much does it rain in Ottumwa in August?

In Ottumwa, in August, during 11.8 rainfall days, 2.2" (56mm) of precipitation is typically accumulated.

When it does not snow in Ottumwa?

June through September are months without snowfall in Ottumwa.

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

The average day length in August in Ottumwa, Iowa, is 13h and 46min.

What time are sunrise and sunset in August in Ottumwa?

In August, on the first day of the month, sunrise is at 6:06 am and sunset at 8:25 pm. On the last day of the month, in Ottumwa, sunrise is at 6:36 am and sunset at 7:43 pm CDT.

How many hours of sunshine does Ottumwa have in August?

The average sunshine duration in August in Ottumwa, Iowa, is 9.9h.

What is the month with the highest UV index in Ottumwa?

June through August, with an average maximum UV index of 6, are months with the highest UV index.

What is the UV index intensity in August in Ottumwa?

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

Average temperature in August - Ottumwa, IA
  • Average high temperature in August: 81.7°F

The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (29.3°F).

  • Average low temperature in August: 63.1°F

The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).

Average pressure in August
Ottumwa, IA

Average pressure in August - Ottumwa, IA
  • Average pressure in August: 29.97"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).

Average wind speed in August
Ottumwa, IA

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

The windiest month (with the highest average wind speed) is January (10.8mph).
The calmest month (with the lowest average wind speed) is August (6.9mph).

Average humidity in August
Ottumwa, IA

Average humidity in August - Ottumwa, IA
  • Average humidity in August: 78%

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

Average rainfall in August
Ottumwa, IA

Average rainfall in August - Ottumwa, IA
  • Average rainfall in August: 2.2"

The wettest month (with the highest rainfall) is May (4.02").
The driest month (with the least rainfall) is January (1.06").

Average rainfall days in August
Ottumwa, IA

Average rainfall days in August - Ottumwa, IA
  • Average rainfall days in August: 11.8 days

The month with the highest number of rainy days is May (17.3 days).
The month with the least rainy days is January (5.2 days).

Average snowfall in August
Ottumwa, IA

Average snowfall in August - Ottumwa, IA
  • Average snowfall in August: 0"

The month with the highest snowfall is February (4.17").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in August
Ottumwa, IA

Average snowfall days in August - Ottumwa, IA
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (10.2 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in August /
Average sunshine in August
Ottumwa, IA

Average daylight in August / Average sunshine in August - Ottumwa, IA
  • 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 July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).

Average sunshine days in August
Ottumwa, IA

Average sunshine days in August - Ottumwa, IA
  • Average sunshine days in August: 16.7 days

The month with the most sunshine days is December (18.9 days).
The month with the least sunshine days is May (11.6 days).

Average UV index in August
Ottumwa, IA

Average UV index in August - Ottumwa, IA
  • Average UV index in August: 6

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

Average cloud cover in August
Ottumwa, IA

Average cloud cover in August - Ottumwa, IA
  • Average cloud cover in August: 29

The month with the most cloud cover is January (Cloud cover 54).
The months with the least cloud cover are August and September (Cloud cover 29).

Average visibility in August
Ottumwa, IA

Average visibility in August - Ottumwa, 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).

Ottumwa, Iowa, USA

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