September weather forecast
Keokuk, IA

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Weather in September

September in Keokuk introduces the early signs of autumn. This transitory month exhibits a noticeable decrease in temperature, as summer gives way to the mellow warmth of fall. The sunlight period slowly shortens and the rainfall also drops to 2.28" (58mm), yet the weather remains generally pleasant. One may find ample time for outdoor activities due to the moderated weather conditions.

Temperature

Transitioning from August to September involves a subtle drop in average high-temperatures, descending from a moderately hot 82.9°F (28.3°C) to a still warm 77.5°F (25.3°C). Throughout September, Keokuk registers a consistent average low-temperature of 57.7°F (14.3°C).

Humidity

In Keokuk, the average relative humidity in September is 74%.

Rainfall

In Keokuk, in September, it is raining for 11.7 days, with typically 2.28" (58mm) of accumulated precipitation. In Keokuk, Iowa, during the entire year, the rain falls for 140.6 days and collects up to 27.72" (704mm) of precipitation.

Snowfall

May through September are months without snowfall.

Daylight

The average length of the day in September is 12h and 27min.
On the first day of the month, sunrise is at 6:33 am and sunset at 7:37 pm. On the last day of September, in Keokuk, sunrise is at 7:01 am and sunset at 6:48 pm CDT.

Sunshine

In September, the average sunshine is 9.4h.

UV index

In September, the average daily maximum UV index in Keokuk is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for the ordinary person.
Note: In September, a daily maximum UV index of 5 leads to the following instructions:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
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Frequently asked questions

What are the temperatures in Keokuk in September?

During September, Keokuk experiences an average high-temperature of 77.5°F (25.3°C) and a low-temperature of 57.7°F (14.3°C). In August, the average heat index (a.k.a. 'feels like', 'felt air temperature'), which represents the influence of relative humidity on air temperature, is appraised at 91.4°F (33°C).

What is the average humidity in September in Keokuk?

In Keokuk, Iowa, the average relative humidity in September is 74%.

How much does it rain in Keokuk in September?

In Keokuk, in September, during 11.7 rainfall days, 2.28" (58mm) of precipitation is typically accumulated.

When it does not snow in Keokuk?

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

Does it snow in Keokuk in September?

In Keokuk, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September in Keokuk?

The average day length in September in Keokuk, Iowa, is 12h and 27min.

When is the sunrise / sunset in September in Keokuk?

On the first day of September in Keokuk, Iowa, sunrise is at 6:33 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:01 am and sunset at 6:48 pm CDT.

How many hours of sunshine does Keokuk have in September?

The average sunshine duration in September in Keokuk, Iowa, is 9.4h.

What is the UV index reading in September in Keokuk?

In Keokuk, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate health threat from unprotected exposure to 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 September
Keokuk, IA

Average temperature in September - Keokuk, IA
  • Average high temperature in September: 77.5°F

The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (31.6°F).

  • Average low temperature in September: 57.7°F

The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (19.2°F).

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Average pressure in September
Keokuk, IA

Average pressure in September - Keokuk, IA
  • Average pressure in September: 30.02"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

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Average wind speed in September
Keokuk, IA

Average wind speed in September - Keokuk, IA
  • Average wind speed in September: 7.5mph

The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.6mph).

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Average humidity in September
Keokuk, IA

Average humidity in September - Keokuk, IA
  • Average humidity in September: 74%

The months with the highest relative humidity are June and July (81%).
The month with the lowest relative humidity is October (70%).

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Average rainfall in September
Keokuk, IA

Average rainfall in September - Keokuk, IA
  • Average rainfall in September: 2.28"

The wettest month (with the highest rainfall) is May (3.9").
The driest month (with the least rainfall) is January (1.34").

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Average rainfall days in September
Keokuk, IA

Average rainfall days in September - Keokuk, IA
  • Average rainfall days in September: 11.7 days

The month with the highest number of rainy days is May (17.3 days).
The month with the least rainy days is February (5.7 days).

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Average snowfall in September
Keokuk, IA

Average snowfall in September - Keokuk, IA
  • Average snowfall in September: 0"

The month with the highest snowfall is January (3.94").
The months with the least snowfall are May, June, July, August and September (0").

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Average snowfall days in September
Keokuk, IA

Average snowfall days in September - Keokuk, IA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (9.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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Average daylight in September /
Average sunshine in September
Keokuk, IA

Average daylight in September / Average sunshine in September - Keokuk, IA
  • Average daylight in September: 12h and 2min

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

  • Average sunshine in September: 9h and 2min

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 18min).

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Average sunshine days in September
Keokuk, IA

Average sunshine days in September - Keokuk, IA
  • Average sunshine days in September: 16.5 days

The month with the most sunshine days is December (18.6 days).
The month with the least sunshine days is June (10.9 days).

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Average UV index in September
Keokuk, IA

Average UV index in September - Keokuk, IA
  • Average UV index in September: 5

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).

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Average cloud cover in September
Keokuk, IA

Average cloud cover in September - Keokuk, IA
  • Average cloud cover in September: 29

The month with the most cloud cover is January (Cloud cover 53).
The months with the least cloud cover are July and August (Cloud cover 28).

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Average visibility in September
Keokuk, IA

Average visibility in September - Keokuk, IA
  • Average visibility in September: 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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Keokuk, Iowa, USA

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