September weather forecast
Shellsburg, IA

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Weather in September

The first month of the autumn, September, is also an agreeable month in Shellsburg, Iowa, with temperature in the range of an average low of 54.7°F (12.6°C) and an average high of 73.2°F (22.9°C).

Temperature

A mild drop in Shellsburg's average high-temperature is observed in September, transitioning from a moderately hot 79.2°F (26.2°C) in August to a pleasant 73.2°F (22.9°C). During the nights in September, Shellsburg experiences a consistent average temperature of 54.7°F (12.6°C).

Humidity

In Shellsburg, the average relative humidity in September is 78%.

Rainfall

In Shellsburg, Iowa, in September, during 11.3 rainfall days, 2.64" (67mm) of precipitation is typically accumulated. In Shellsburg, during the entire year, the rain falls for 138.6 days and collects up to 27.8" (706mm) of precipitation.

Snowfall

In Shellsburg, Iowa, snow does not fall in June through September.

Daylight

In September, the average length of the day is 12h and 28min.
On the first day of the month, sunrise is at 6:33 am and sunset at 7:40 pm. On the last day of September, sunrise is at 7:04 am and sunset at 6:50 pm CDT.

Sunshine

The average sunshine in September is 9.1h.

UV index

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.
Note: In September, the UV index of 4 transforms into the following advice:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage.
Updated: Aug 11, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Shellsburg in September?

In September, in Shellsburg, the average high-temperature is 73.2°F (22.9°C), and the average low-temperature is 54.7°F (12.6°C).

What is the average humidity in September in Shellsburg?

The average relative humidity in September in Shellsburg, Iowa, is 78%.

How many days does it rain in September?

In Shellsburg, during September, the rain falls for 11.3 days and regularly aggregates up to 2.64" (67mm) of precipitation.

When it does not snow?

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

Does it snow in September?

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

What is the average length of the day in September?

The average day length in September is 12h and 28min.

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:33 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:50 pm CDT.

How long on average sun shines in September?

The average sunshine duration in September is 9.1h.

What is the UV index intensity in September?

The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health threat from unsafe exposure to Sun's UV rays.
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
Shellsburg, IA

Average temperature in September - Shellsburg, 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 (25.3°F).

  • Average low temperature in September: 54.7°F

The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (13.5°F).

Average pressure in September
Shellsburg, IA

Average pressure in September - Shellsburg, 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
Shellsburg, IA

Average wind speed in September - Shellsburg, IA
  • Average wind speed in September: 8mph

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

Average humidity in September
Shellsburg, IA

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

The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is October (73%).

Average rainfall in September
Shellsburg, IA

Average rainfall in September - Shellsburg, IA
  • Average rainfall in September: 2.64"

The wettest month (with the highest rainfall) is May (4.37").
The driest months (with the least rainfall) are January and February (1.18").

Average rainfall days in September
Shellsburg, IA

Average rainfall days in September - Shellsburg, IA
  • Average rainfall days in September: 11.3 days

The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is January (4.8 days).

Average snowfall in September
Shellsburg, IA

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

The month with the highest snowfall is January (5.43").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Shellsburg, IA

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

The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

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

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 September: 9h and 1min

The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).

Average sunshine days in September
Shellsburg, IA

Average sunshine days in September - Shellsburg, IA
  • Average sunshine days in September: 16.4 days

The month with the most sunshine days is October (17.6 days).
The month with the least sunshine days is June (9.9 days).

Average UV index in September
Shellsburg, IA

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

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

Average cloud cover in September
Shellsburg, IA

Average cloud cover in September - Shellsburg, IA
  • Average cloud cover in September: 31

The month with the most cloud cover is January (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 30).

Average visibility in September
Shellsburg, IA

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

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

Shellsburg, Iowa, USA

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