September weather forecast
O'Neill, IA

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Weather in September

September, the first month of the autumn in O'Neill, is still a pleasant month, with temperature in the range of an average high of 72°F (22.2°C) and an average low of 53.2°F (11.8°C).

Temperature

In O'Neill, the average high-temperature in September slightly decreases from a warm 78.4°F (25.8°C) in August to a pleasant 72°F (22.2°C). O'Neill records a steady low-temperature average of 53.2°F (11.8°C) during September.

Humidity

The average relative humidity in September in O'Neill is 80%.

Rainfall

In O'Neill, in September, it is raining for 12.5 days, with typically 2.56" (65mm) of accumulated precipitation. In O'Neill, during the entire year, the rain falls for 139.6 days and collects up to 24.92" (633mm) of precipitation.

Snowfall

May through September are months without snowfall.

Daylight

The average length of the day in September in O'Neill, Iowa, is 12h and 29min.
On the first day of September, sunrise is at 6:29 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:00 am and sunset at 6:46 pm CDT.

Sunshine

The average sunshine in September is 8.9h.

UV index

In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.
Note: An average UV index of 4 in September transforms into this advice:
Exercise care. People with light skin might get burns in fewer than 30 minutes. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses.
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Frequently asked questions

What is the temperature in September in O'Neill?

An average high-temperature, in September, in O'Neill, is 72°F (22.2°C) and the average low-temperature is 53.2°F (11.8°C).

What is the average humidity in September in O'Neill?

In September, the average relative humidity in O'Neill is 80%.

How much does it rain in O'Neill in September?

In O'Neill, in September, during 12.5 rainfall days, 2.56" (65mm) of precipitation is typically accumulated.

When it does not snow in O'Neill?

May through September are months without snowfall in O'Neill.

Does it snow in O'Neill in September?

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

What is the average length of the day in September in O'Neill?

In O'Neill, Iowa, the average day length in September is 12h and 29min.

When are sunrise and sunset in September in O'Neill?

In September, on the first day of the month, sunrise is at 6:29 am and sunset at 7:37 pm. On the last day of the month, in O'Neill, Iowa, sunrise is at 7:00 am and sunset at 6:46 pm CDT.

How many hours of sunshine does O'Neill have in September?

The average sunshine duration in September in O'Neill, Iowa, is 8.9h.

How high is the UV index in September in O'Neill?

The average daily maximum UV index in September in O'Neill, Iowa, is 4. A UV Index estimate of 3 to 5 represents a moderate vulnerability 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
O'Neill, IA

Average temperature in September - O
  • Average high temperature in September: 72°F

The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (24.3°F).

  • Average low temperature in September: 53.2°F

The month with the highest average low temperature is July (62.8°F).
The coldest month (with the lowest average low temperature) is January (11.7°F).

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Average pressure in September
O'Neill, IA

Average pressure in September - O
  • 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
O'Neill, IA

Average wind speed in September - O
  • Average wind speed in September: 7.9mph

The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).

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Average humidity in September
O'Neill, IA

Average humidity in September - O
  • Average humidity in September: 80%

The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is October (75%).

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Average rainfall in September
O'Neill, IA

Average rainfall in September - O
  • Average rainfall in September: 2.56"

The wettest months (with the highest rainfall) are May and June (3.54").
The driest month (with the least rainfall) is December (0.98").

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Average rainfall days in September
O'Neill, IA

Average rainfall days in September - O
  • Average rainfall days in September: 12.5 days

The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is February (4.1 days).

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Average snowfall in September
O'Neill, IA

Average snowfall in September - O
  • Average snowfall in September: 0"

The month with the highest snowfall is January (4.29").
The months with the least snowfall are May, June, July, August and September (0").

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Average snowfall days in September
O'Neill, IA

Average snowfall days in September - O
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (13.7 days).
The months with the least snowfall days are June, July, August and September (0 days).

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Average daylight in September /
Average sunshine in September
O'Neill, IA

Average daylight in September / Average sunshine in September - O
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).

  • Average sunshine in September: 8h and 5min

The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).

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Average sunshine days in September
O'Neill, IA

Average sunshine days in September - O
  • Average sunshine days in September: 15.1 days

The month with the most sunshine days is November (17.9 days).
The month with the least sunshine days is May (9.4 days).

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Average UV index in September
O'Neill, IA

Average UV index in September - O
  • Average UV index in September: 4

The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January, November and December (UV index 1).

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Average cloud cover in September
O'Neill, IA

Average cloud cover in September - O
  • Average cloud cover in September: 33

The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 32).

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Average visibility in September
O'Neill, IA

Average visibility in September - O
  • Average visibility in September: 6mi

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

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O'Neill, Iowa, USA

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