September weather forecast
Cedar Rapids, IA

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Nice aerial capture of the skyline over Cedar Rapids in Iowa
Nice aerial capture of the skyline over Cedar Rapids in Iowa

Weather in September

In September, Cedar Rapids navigates its way towards fall with more pleasant temperatures and a decreased humidity index. However, rainfall increases to 1.73" (44mm), marking the cityscape with the variegated colors of fall. Despite the reduced daylight hours, the amount of sunshine remains significant, making the short days vibrant and inviting. As the temperatures cool down, so do the winds, indicating the slow and steady pivot towards the colder months. UV levels drop, making it a suitable weather for long strolls amidst the autumn leaves.

Temperature

Cedar Rapids, Iowa, commences September with an average high-temperature of a still moderately hot 74.3°F (23.5°C), maintaining a close resemblance to the previous month. During the month of September, an average low-temperature of 55.2°F (12.9°C) is recorded.

Humidity

In September, the average relative humidity is 77%.

Rainfall

In Cedar Rapids, Iowa, in September, during 10.9 rainfall days, 1.73" (44mm) of precipitation is typically accumulated. In Cedar Rapids, during the entire year, the rain falls for 120.7 days and collects up to 18.31" (465mm) of precipitation.

Snowfall

May through September are months without snowfall.

Daylight

In Cedar Rapids, the average length of the day in September is 12h and 28min.
On the first day of September, sunrise is at 6:33 am and sunset at 7:39 pm. On the last day of the month, sunrise is at 7:03 am and sunset at 6:49 pm CDT.

Sunshine

In Cedar Rapids, the average sunshine in September is 9.3h.

UV index

In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the average person.
Note: The maximum UV index of 4 during September translates into these guidelines:
Guard yourself - An obligation to protect skin and eyes from harm exists. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.
Updated: Jul 21, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in September?

The high-temperature, in September, in Cedar Rapids, records 74.3°F (23.5°C), while the low-temperature is 55.2°F (12.9°C). In July, the average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which combines air temperature and relative humidity, is computed to be 86°F (30°C).

What is the average humidity in September?

The average relative humidity in September is 77%.

How much does it rain in September?

In Cedar Rapids, during September, the rain falls for 10.9 days and regularly aggregates up to 1.73" (44mm) of precipitation.

When it does not snow?

May through September are months without snowfall.

Does it snow in September?

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

How many hours of daylight does Cedar Rapids have in September?

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

When is the sunrise / sunset in September?

On the first day of September, sunrise is at 6:33 am and sunset at 7:39 pm. On the last day of the month, sunrise is at 7:03 am and sunset at 6:49 pm CDT.

How many hours of sunshine does Cedar Rapids have in September?

In September, the average sunshine duration is 9.3h.

How high is the UV index in September?

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate vulnerability 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
Cedar Rapids, IA

Average temperature in September - Cedar Rapids, IA
  • Average high temperature in September: 74.3°F

The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (26.2°F).

  • Average low temperature in September: 55.2°F

The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (14.2°F).

Average pressure in September
Cedar Rapids, IA

Average pressure in September - Cedar Rapids, 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 (29.9"Hg).

Average wind speed in September
Cedar Rapids, IA

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

The windiest months (with the highest average wind speed) are January and April (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).

Average humidity in September
Cedar Rapids, IA

Average humidity in September - Cedar Rapids, IA
  • Average humidity in September: 77%

The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is October (73%).

Average rainfall in September
Cedar Rapids, IA

Average rainfall in September - Cedar Rapids, IA
  • Average rainfall in September: 1.73"

The wettest month (with the highest rainfall) is May (3.07").
The driest months (with the least rainfall) are January and February (0.63").

Average rainfall days in September
Cedar Rapids, IA

Average rainfall days in September - Cedar Rapids, IA
  • Average rainfall days in September: 10.9 days

The month with the highest number of rainy days is May (16 days).
The month with the least rainy days is February (3 days).

Average snowfall in September
Cedar Rapids, IA

Average snowfall in September - Cedar Rapids, IA
  • Average snowfall in September: 0"

The month with the highest snowfall is January (2.64").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Cedar Rapids, IA

Average snowfall days in September - Cedar Rapids, IA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (10.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Cedar Rapids, IA

Average daylight in September / Average sunshine in September - Cedar Rapids, 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 2min

The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

Average sunshine days in September
Cedar Rapids, IA

Average sunshine days in September - Cedar Rapids, IA
  • Average sunshine days in September: 18.2 days

The month with the most sunshine days is October (19.9 days).
The month with the least sunshine days is June (11.8 days).

Average UV index in September
Cedar Rapids, IA

Average UV index in September - Cedar Rapids, IA
  • Average UV index in September: 4

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).

Average cloud cover in September
Cedar Rapids, IA

Average cloud cover in September - Cedar Rapids, IA
  • Average cloud cover in September: 30

The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are August and September (Cloud cover 30).

Average visibility in September
Cedar Rapids, IA

Average visibility in September - Cedar Rapids, IA
  • Average visibility in September: 6mi

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

Cedar Rapids, Iowa, USA

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