September weather forecast and climate
Portland, AR

Weather in September

September, the first month of the autumn, in Portland, is still a hot month, with average temperature fluctuating between 86°F (30°C) and 67.3°F (19.6°C).

Temperature

In Portland, the average high-temperature is essentially the same as in August - a still hot 86°F (30°C). In Portland, the average low-temperature is 67.3°F (19.6°C).

Heat index

In September, the average heat index is calculated to a sweltering 95.9°F (35.5°C). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
Note that heat index values are valued for light wind and location in the shade. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like', 'apparent temperature', 'real feel', or 'felt air temperature', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. Additional factors like wind, differences in body mass, height, and shape, metabolic differences, and activity influence one's weather impression. Be aware that direct exposure to sunlight increases heat impact, and may raise the heat index additionally, by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.
The human body normally cools itself by perspiration. Excessive warmth is eliminated from the body by evaporation of sweat. When the relative humidity is high, the evaporation rate is reduced. The warmth is removed from the body at a lower rate, causing the body to retain more heat than it would in dry air. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.

Humidity

In September, the average relative humidity in Portland is 72%.

Rainfall

In Portland, during 12.8 rainfall days, 2.72" (69mm) of precipitation is typically accumulated. In Portland, during the entire year, the rain falls for 158.8 days and collects up to 40.67" (1033mm) of precipitation.

Snowfall

April through October and December are months without snowfall.

Daylight

The average length of the day in Portland is 12.4h.

Sunshine

The average sunshine is 9.9h.

UV index

In September, the average daily maximum UV index is 6. A UV Index value of 6 to 7 symbolizes a high health vulnerability from unprotected exposure to the Sun's UV rays for ordinary individuals.
Note: The daily maximum UV index of 6 interpret into the following advice:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.
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FAQ

What is the temperature in September in Portland?

In September, the average high-temperature is 86°F (30°C), and the average low-temperature is 67.3°F (19.6°C). The average heat index (a.k.a. 'real feel', 'felt air temperature'), that factores the actual air temperature with the relative humidity, in September is calculated to 95.9°F (35.5°C).

What is the average humidity in September in Portland?

In September, the average relative humidity in Portland, Arkansas, is 72%.

How many days does it rain in September in Portland?

In Portland, during September, the rain falls for 12.8 days and regularly aggregates up to 2.72" (69mm) of precipitation.

When it does not snow in Portland?

April through October and December are months without snowfall.

What is the average length of the day in September in Portland?

The average length of the day in September in Portland is 12.4h.

How many hours of sunshine does Portland have in September?

In Portland, Arkansas, the average sunshine in September is 9.9h.

What is the UV index intensity in September in Portland?

In Portland, Arkansas, the average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high health vulnerability from unprotected exposure to the UV radiation.

Average temperature in September
Portland, AR

Average temperature in September - Portland, AR
  • Average high temperature in September: 86°F

The warmest month (with the highest average high temperature) is July (90.7°F).
The month with the lowest average high temperature is January (51.6°F).

  • Average low temperature in September: 67.3°F

The month with the highest average low temperature is July (73.6°F).
The coldest month (with the lowest average low temperature) is January (38.1°F).

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Average pressure in September
Portland, AR

Average pressure in September - Portland, AR
  • Average pressure in September: 29.99"

The month with the highest atmospheric pressure is January (30.17").
The month with the lowest atmospheric pressure is June (29.95").

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Average wind speed in September
Portland, AR

Average wind speed in September - Portland, AR
  • Average wind speed in September: 6mph

The windiest month (with the highest average wind speed) is February (9.4mph).
The calmest month (with the lowest average wind speed) is August (5.5mph).

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Average humidity in September
Portland, AR

Average humidity in September - Portland, AR
  • Average humidity in September: 72%

Months with the highest relative humidity are February and March (79%).
The month with the lowest relative humidity is October (67%).

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Average rainfall in September
Portland, AR

Average rainfall in September - Portland, AR
  • Average rainfall in September: 2.72"

The wettest month (with the highest rainfall) is April (4.49").
The driest month (with the least rainfall) is November (2.44").

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Average rainfall days in September
Portland, AR

Average rainfall days in September - Portland, AR
  • Average rainfall days in September: 12.8 days

The month with the highest number of rainy days is July (16.7 days).
The month with the least rainy days is October (9.3 days).

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Average snowfall in September
Portland, AR

Average snowfall in September - Portland, AR
  • Average snowfall in September: 0"

The month with the highest snowfall is February (0.43").
Months with the least snowfall are April, May, June, July, August, September, October and December (0").

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Average snowfall days in September
Portland, AR

Average snowfall days in September - Portland, AR
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (1.2 days).
Months with the least snowfall days are April, May, June, July, August, September, October and December (0 days).

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Average daylight in September /
Average sunshine in September
Portland, AR

Average daylight in September / Average sunshine in September - Portland, AR
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.3h).
The month with the shortest days is December (Average daylight: 10h).

  • Average sunshine in September: 9.9h

The month with the most sunshine is June (Average sunshine: 10.8h).
The month with the least sunshine is February (Average sunshine: 4.8h).

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Average sunshine days in September
Portland, AR

Average sunshine days in September - Portland, AR
  • Average sunshine days in September: 14.8 days

The month with the most sunshine days is October (19.6 days).
The month with the least sunshine days is July (12 days).

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Average UV index in September
Portland, AR

Average UV index in September - Portland, AR
  • Average UV index in September: 6

Months with the highest UV index are June, July and August (UV index 7).
Months with the lowest UV index are January and December (UV index 3).

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Average cloud cover in September
Portland, AR

Average cloud cover in September - Portland, AR
  • Average cloud cover in September: 27

The month with the most cloud cover is February (Cloud cover 46).
The month with the least cloud cover is June (Cloud cover 25).

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Average visibility in September
Portland, AR

Average visibility in September - Portland, AR
  • Average visibility in September: 6mi

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

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