September weather forecast
Dewar, IA

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Weather in September

The first month of the autumn, September, is also an agreeable month in Dewar, Iowa, with an average temperature varying between 73.2°F (22.9°C) and 54.5°F (12.5°C).

Temperature

Dewar's progression into September involves a gentle drop in the average high-temperature, from a moderately hot 78.6°F (25.9°C) in August to a pleasant 73.2°F (22.9°C). An average low-temperature of 54.5°F (12.5°C) is recorded during the nights in September.

Humidity

The average relative humidity in September is 78%.

Rainfall

In Dewar, in September, it is raining for 11.2 days, with typically 2.48" (63mm) of accumulated precipitation. Throughout the year, there are 133.6 rainfall days, and 28.27" (718mm) of precipitation is accumulated.

Snowfall

June through September are months without snowfall.

Daylight

The average length of the day in September is 12h and 28min.
On the first day of September, sunrise is at 6:34 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 6:51 pm CDT.

Sunshine

The average sunshine in September is 9.1h.

UV index

In Dewar, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for ordinary individuals.
Note: The daily high UV index of 4 during September translates into the following recommendations:
Take precautions - Protection against skin and eye damage is obliged. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
Updated: Aug 25, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in September?

During September, Dewar experiences an average high-temperature of 73.2°F (22.9°C) and a low-temperature of 54.5°F (12.5°C).

What is the average humidity in September?

The average relative humidity in September is 78%.

How many days does it rain in September?

In Dewar, in September, during 11.2 rainfall days, 2.48" (63mm) of precipitation is typically accumulated.

When it does not snow?

June through September are months without snowfall.

Does it snow in September?

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

How many hours of daylight does Dewar have in September?

In Dewar, the average day length in September is 12h and 28min.

When is the sunrise / sunset in September?

On the first day of September, sunrise is at 6:34 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 6:51 pm CDT.

How long on average sun shines in September?

In September, the average sunshine duration is 9.1h.

What is the UV index reading in September in Dewar?

In Dewar, Iowa, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium hazard to health 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
Dewar, IA

Average temperature in September - Dewar, IA
  • Average high temperature in September: 73.2°F

The warmest month (with the highest average high temperature) is July (80.1°F).
The month with the lowest average high temperature is January (24.3°F).

  • Average low temperature in September: 54.5°F

The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (12°F).

Average pressure in September
Dewar, IA

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

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).

Average wind speed in September
Dewar, IA

Average wind speed in September - Dewar, IA
  • Average wind speed in September: 8.2mph

The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest month (with the lowest average wind speed) is August (7mph).

Average humidity in September
Dewar, IA

Average humidity in September - Dewar, IA
  • Average humidity in September: 78%

The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is October (72%).

Average rainfall in September
Dewar, IA

Average rainfall in September - Dewar, IA
  • Average rainfall in September: 2.48"

The wettest month (with the highest rainfall) is June (4.29").
The driest months (with the least rainfall) are January and February (1.02").

Average rainfall days in September
Dewar, IA

Average rainfall days in September - Dewar, IA
  • Average rainfall days in September: 11.2 days

The month with the highest number of rainy days is June (18.1 days).
The month with the least rainy days is February (4 days).

Average snowfall in September
Dewar, IA

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

The month with the highest snowfall is January (4.21").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Dewar, IA

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

The month with the highest number of snowfall days is January (11.5 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in September / Average sunshine in September - Dewar, IA
  • Average daylight in September: 12h and 3min

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 6min).

  • Average sunshine in September: 9h and 1min

The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).

Average sunshine days in September
Dewar, IA

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

The month with the most sunshine days is October (17.8 days).
The month with the least sunshine days is June (10 days).

Average UV index in September
Dewar, IA

Average UV index in September - Dewar, IA
  • Average UV index in September: 4

The month with the highest UV index is June (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in September
Dewar, IA

Average cloud cover in September - Dewar, IA
  • Average cloud cover in September: 32

The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 31).

Average visibility in September
Dewar, IA

Average visibility in September - Dewar, IA
  • Average visibility in September: 6mi

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

Dewar, Iowa, USA

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