September weather forecast
Monticello, IA

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Weather in September

September, the first month of the autumn in Monticello, is still a pleasant month, with an average temperature fluctuating between 73°F (22.8°C) and 54.3°F (12.4°C).

Temperature

Monticello records a mild change in average high-temperature during September, easing from a moderately hot 78.6°F (25.9°C) in August to an agreeable 73°F (22.8°C). During the nights in September, Monticello observes an average low-temperature of 54.3°F (12.4°C).

Humidity

The average relative humidity in September in Monticello is 79%.

Rainfall

In September, in Monticello, the rain falls for 11.4 days. Throughout September, 2.52" (64mm) of precipitation is accumulated. Throughout the year, there are 142.5 rainfall days, and 28.27" (718mm) of precipitation is accumulated.

Snowfall

In Monticello, snow does not fall in May through September.

Daylight

The average length of the day in September in Monticello is 12h and 28min.
On the first day of the month, sunrise is at 6:30 am and sunset at 7:38 pm. On the last day of September, sunrise is at 7:01 am and sunset at 6:47 pm CDT.

Sunshine

In September, the average sunshine is 9.1h.

UV index

The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: During September, 4 as the daily maximum UV index converts into the following advice:
Put precautions into practice - Guidance to elude sunburn is provided. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
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Frequently asked questions

What is the temperature in September in Monticello?

The high-temperature, in September, in Monticello, records 73°F (22.8°C), while the low-temperature is 54.3°F (12.4°C).

What is the average humidity in September in Monticello?

In Monticello, the average relative humidity in September is 79%.

How many days does it rain in September in Monticello?

In September, the rain falls for 11.4 days. Throughout September, 2.52" (64mm) of precipitation is accumulated.

When it does not snow in Monticello?

May through September are months without snowfall.

Does it snow in Monticello in September?

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

How many hours of daylight does Monticello have in September?

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

When is the sunrise / sunset in September in Monticello?

On the first day of September in Monticello, Iowa, sunrise is at 6:30 am and sunset at 7:38 pm. On the last day of the month, sunrise is at 7:01 am and sunset at 6:47 pm CDT.

How long on average sun shines in September in Monticello?

The average sunshine duration in September in Monticello, Iowa, is 9.1h.

What is the UV index reading in September in Monticello?

In Monticello, Iowa, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health threat from 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
Monticello, IA

Average temperature in September - Monticello, IA
  • Average high temperature in September: 73°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 (25.2°F).

  • Average low temperature in September: 54.3°F

The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is January (13.3°F).

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Average pressure in September
Monticello, IA

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

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

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Average wind speed in September
Monticello, IA

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

The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (6.9mph).

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Average humidity in September
Monticello, IA

Average humidity in September - Monticello, IA
  • Average humidity in September: 79%

The months with the highest relative humidity are January and February (86%).
The month with the lowest relative humidity is October (74%).

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Average rainfall in September
Monticello, IA

Average rainfall in September - Monticello, IA
  • Average rainfall in September: 2.52"

The wettest month (with the highest rainfall) is May (4.25").
The driest months (with the least rainfall) are January and February (1.26").

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Average rainfall days in September
Monticello, IA

Average rainfall days in September - Monticello, IA
  • Average rainfall days in September: 11.4 days

The month with the highest number of rainy days is May (18.6 days).
The month with the least rainy days is January (5.2 days).

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Average snowfall in September
Monticello, IA

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

The month with the highest snowfall is January (5.04").
The months with the least snowfall are May, June, July, August and September (0").

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Average snowfall days in September
Monticello, IA

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

The month with the highest number of snowfall days is January (12.1 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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

Average daylight in September / Average sunshine in September - Monticello, 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 months with the most sunshine are July and August (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).

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Average sunshine days in September
Monticello, IA

Average sunshine days in September - Monticello, IA
  • Average sunshine days in September: 17 days

The month with the most sunshine days is September (17 days).
The month with the least sunshine days is June (10.5 days).

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Average UV index in September
Monticello, IA

Average UV index in September - Monticello, 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).

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Average cloud cover in September
Monticello, IA

Average cloud cover in September - Monticello, 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 30).

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Average visibility in September
Monticello, IA

Average visibility in September - Monticello, 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).

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Monticello, Iowa, USA

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