September weather forecast
Leon, IA

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Weather in September

The first month of the autumn, September, is still a warm month in Leon, Iowa, with an average temperature ranging between max 76.1°F (24.5°C) and min 56.3°F (13.5°C).

Temperature

The arrival of September corresponds with a light shift in temperature, down from 81.9°F (27.7°C) in August to a still moderately hot 76.1°F (24.5°C). In September, Leon experiences an average nighttime temperature of 56.3°F (13.5°C).

Humidity

In Leon, the average relative humidity in September is 77%.

Rainfall

In Leon, in September, during 11.5 rainfall days, 2.24" (57mm) of precipitation is typically accumulated. In Leon, during the entire year, the rain falls for 132.4 days and collects up to 20.24" (514mm) of precipitation.

Snowfall

June through September are months without snowfall.

Daylight

In September, the average length of the day is 12h and 27min.
On the first day of September, sunrise is at 6:42 am and sunset at 7:46 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 6:58 pm CDT.

Sunshine

In September, the average sunshine is 9.4h.

UV index

In Leon, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for the average person.
Note: An average maximum UV index of 4 in September leads to these recommendations:
Act with care - Obligation to protect against skin and eye damage is highlighted. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Updated: Jun 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

In Leon, 76.1°F (24.5°C) is the average high-temperature and 56.3°F (13.5°C) is the average low-temperature during September. In August, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, is computed to be 87.8°F (31°C).

What is the average humidity in September?

In Leon, the average relative humidity in September is 77%.

How many days does it rain in September?

In September, the rain falls for 11.5 days. Throughout September, 2.24" (57mm) of precipitation is accumulated.

When it does not snow?

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

Does it snow in September?

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

What is the average length of the day in September?

In September, the average day length is 12h and 27min.

What time are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:42 am and sunset at 7:46 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 6:58 pm CDT.

How long on average sun shines in September?

In Leon, the average sunshine duration in September is 9.4h.

How high is the UV index in September?

In September, the average daily maximum UV index is 4. A UV Index estimate 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
Leon, IA

Average temperature in September - Leon, IA
  • Average high temperature in September: 76.1°F

The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is January (30.6°F).

  • Average low temperature in September: 56.3°F

The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (16.9°F).

Average pressure in September
Leon, IA

Average pressure in September - Leon, 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 (29.89"Hg).

Average wind speed in September
Leon, IA

Average wind speed in September - Leon, IA
  • Average wind speed in September: 7.9mph

The windiest months (with the highest average wind speed) are January, February and March (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.9mph).

Average humidity in September
Leon, IA

Average humidity in September - Leon, IA
  • Average humidity in September: 77%

The month with the highest relative humidity is June (83%).
The month with the lowest relative humidity is October (72%).

Average rainfall in September
Leon, IA

Average rainfall in September - Leon, IA
  • Average rainfall in September: 2.24"

The wettest month (with the highest rainfall) is June (3.43").
The driest months (with the least rainfall) are January and December (0.67").

Average rainfall days in September
Leon, IA

Average rainfall days in September - Leon, IA
  • Average rainfall days in September: 11.5 days

The month with the highest number of rainy days is June (17.3 days).
The month with the least rainy days is January (4.8 days).

Average snowfall in September
Leon, IA

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

The month with the highest snowfall is January (2.72").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Leon, IA

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

The month with the highest number of snowfall days is January (8.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in September / Average sunshine in September - Leon, 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 24min).

Average sunshine days in September
Leon, IA

Average sunshine days in September - Leon, IA
  • Average sunshine days in September: 16 days

The month with the most sunshine days is December (20.3 days).
The month with the least sunshine days is June (8.9 days).

Average UV index in September
Leon, IA

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

The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).

Average cloud cover in September
Leon, IA

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

The month with the most cloud cover is January (Cloud cover 51).
The month with the least cloud cover is July (Cloud cover 28).

Average visibility in September
Leon, IA

Average visibility in September - Leon, 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).

Leon, Iowa, USA

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