September weather forecast
Boone, IA

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Weather in September

September ushers in the start of fall in Boone. With it, the temperatures begin a steady descent, and the city surrounds itself with spectacular fall foliage. As temperatures mildly drop, September poses the beginning of more comfortable weather following a humid summer. Regarding precipitation, the month observes 2.4" (61mm) of rainfall, slightly higher than the preceding August. Despite shorter days, September's lovely fall weather complements the extravagant rainbow-draped cityscape of Boone.

Temperature

September's climate in Boone shows a minor adjustment in average high-temperatures to a still warm 74.8°F (23.8°C) from August's 79.9°F (26.6°C). In Boone, in September, the average low-temperature is a moderate 55.8°F (13.2°C).

Humidity

In September, the average relative humidity is 76%.

Rainfall

In Boone, in September, it is raining for 11.1 days, with typically 2.4" (61mm) of accumulated precipitation. In Boone, during the entire year, the rain falls for 123.3 days and collects up to 20.98" (533mm) of precipitation.

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 in Boone, sunrise is at 6:41 am and sunset at 7:48 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 6:58 pm CDT.

Sunshine

In September, the average sunshine in Boone is 9.3h.

UV index

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The maximum daily UV index, 4 in September, converts into the following recommendations:
Act with care - The need to guard against sun damage is communicated. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures in Boone?

In Boone, in September, the average high-temperature is 74.8°F (23.8°C), and the average low-temperature is 55.8°F (13.2°C). In July, the average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which combines relative humidity and air temperature, is computed to be 87.8°F (31°C).

What is the average humidity in September in Boone?

The average relative humidity in September in Boone, Iowa, is 76%.

How many days does it rain in September in Boone?

In Boone, Iowa, in September, during 11.1 rainfall days, 2.4" (61mm) of precipitation is typically accumulated.

When it does not snow in Boone?

June through September are months without snowfall in Boone.

Does it snow in Boone in September?

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

How many hours of daylight does Boone have in September?

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

What time are sunrise and sunset in September in Boone?

On the first day of September, sunrise is at 6:41 am and sunset at 7:48 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 6:58 pm CDT.

How many hours of sunshine does Boone have in September?

In September, the average sunshine duration in Boone, Iowa, is 9.3h.

How high is the UV index in September in Boone?

The average daily maximum UV index in September in Boone, Iowa, 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
Boone, IA

Average temperature in September - Boone, IA
  • Average high temperature in September: 74.8°F

The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (26.4°F).

  • Average low temperature in September: 55.8°F

The month with the highest average low temperature is July (64.4°F).
The coldest month (with the lowest average low temperature) is January (13.1°F).

Average pressure in September
Boone, IA

Average pressure in September - Boone, IA
  • Average pressure in September: 30.01"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).

Average wind speed in September
Boone, IA

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

The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (7.1mph).

Average humidity in September
Boone, IA

Average humidity in September - Boone, IA
  • Average humidity in September: 76%

The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is October (69%).

Average rainfall in September
Boone, IA

Average rainfall in September - Boone, IA
  • Average rainfall in September: 2.4"

The wettest month (with the highest rainfall) is June (3.35").
The driest month (with the least rainfall) is January (0.67").

Average rainfall days in September
Boone, IA

Average rainfall days in September - Boone, IA
  • Average rainfall days in September: 11.1 days

The month with the highest number of rainy days is June (17.4 days).
The month with the least rainy days is February (3.2 days).

Average snowfall in September
Boone, IA

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

The month with the highest snowfall is February (3.07").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Boone, IA

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

The month with the highest number of snowfall days is January (10.9 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in September / Average sunshine in September - Boone, 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 6min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).

Average sunshine days in September
Boone, IA

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

The month with the most sunshine days is October (19.5 days).
The month with the least sunshine days is June (10.5 days).

Average UV index in September
Boone, IA

Average UV index in September - Boone, 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, February, October, November and December (UV index 2).

Average cloud cover in September
Boone, IA

Average cloud cover in September - Boone, IA
  • Average cloud cover in September: 30

The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is September (Cloud cover 30).

Average visibility in September
Boone, IA

Average visibility in September - Boone, 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).

Boone, Iowa, USA

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