September weather forecast
Portal, AZ

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Weather in September

The month of September in Portal, Arizona, indicates the onset of Fall, with declining temperatures being the dominant feature. The transition becomes evident from the lowering temperatures and shorter daylight hours. The rainfall sees a more significant drop from August to September, sliding down to about 1.22" (31mm). The decline in rainfall occurs in tandem with the reduction in humidity, leading to the cooler atmospheric conditions that presage the Fall season.

Temperature

The onset of September results in a small decrease in the average high-temperature, moderately receding from a hot 89.6°F (32°C) in August to a warm 84.2°F (29°C). The month of September records an average low-temperature of 66.4°F (19.1°C) in Portal.

Heat index

The heat index value for September is estimated at 84.2°F (29°C). Exposure and extended activity could potentially cause a state of fatigue and lead to heat cramps.
It is essential to grasp that the heat index's numbers are for shade and light wind settings. A rise of up to 15 Fahrenheit (8 Celsius) degrees in the heat index could result from direct sunlight.
Note: The heat index, also known as 'real feel' or 'felt air temperature', gauges the sensation of temperature factoring in the air's moisture content. Metabolic differences, pregnancy status, and the level of physical activity are additional factors influencing an individual's weather perception. Awareness is key; direct sunlight can enhance the weather's impact, possibly boosting the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Children commonly overlook the importance of rest and fluid replenishment. Thirst, being a delayed sign of dehydration, emphasizes the need to keep hydration up, especially during lengthy physical activities.

Humidity

In September, the average relative humidity in Portal is 43%.

Rainfall

In September, in Portal, Arizona, the rain falls for 9.5 days. Throughout September, 1.22" (31mm) of precipitation is accumulated. Throughout the year, in Portal, there are 73.4 rainfall days, and 7.91" (201mm) of precipitation is accumulated.

Snowfall

April through October are months without snowfall in Portal.

Daylight

In Portal, the average length of the day in September is 12h and 21min.
On the first day of the month, sunrise is at 5:52 am and sunset at 6:40 pm. On the last day of September, in Portal, sunrise is at 6:10 am and sunset at 6:02 pm MST.

Sunshine

The average sunshine in September is 10.7h.

UV index

In September, the average daily maximum UV index in Portal is 6. A UV Index value of 6 to 7 symbolizes a high health risk from unsafe exposure to UV radiation for the ordinary person.
Note: In September, the maximum UV index of 6 suggests this advice:
Ward off overexposure. Defence against solar harm is crucial. It's important to stay in the shade and limit exposure to the sun from 10 a.m. to 4 p.m., when UV radiation is most intense, although remember that shade structures may not provide full sun protection. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
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Frequently asked questions

How hot is it in Portal in September?

In Portal, 84.2°F (29°C) is the average high-temperature and 66.4°F (19.1°C) is the average low-temperature during September. The average heat index (a.k.a. 'felt air temperature', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, in September is estimated at 84.2°F (29°C).

What is the average humidity in September in Portal?

The average relative humidity in September in Portal, Arizona, is 43%.

How much does it rain in Portal in September?

In September, the rain falls for 9.5 days. Throughout September, 1.22" (31mm) of precipitation is accumulated.

When it does not snow in Portal?

April through October are months without snowfall.

How many hours of daylight does Portal have in September?

The average day length in September is 12h and 21min.

What time are sunrise and sunset in September in Portal?

On the first day of September in Portal, sunrise is at 5:52 am and sunset at 6:40 pm. On the last day of the month, sunrise is at 6:10 am and sunset at 6:02 pm MST.

How many hours of sunshine does Portal have in September?

In Portal, the average sunshine duration in September is 10.7h.

How high is the UV index in September in Portal?

In Portal, Arizona, the average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high health 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
Portal, AZ

Average temperature in September - Portal, AZ
  • Average high temperature in September: 84.2°F

The warmest month (with the highest average high temperature) is June (92.8°F).
The month with the lowest average high temperature is December (54.5°F).

  • Average low temperature in September: 66.4°F

The month with the highest average low temperature is July (73°F).
The coldest month (with the lowest average low temperature) is January (36.3°F).

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Average pressure in September
Portal, AZ

Average pressure in September - Portal, AZ
  • Average pressure in September: 29.94"Hg

The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).

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Average wind speed in September
Portal, AZ

Average wind speed in September - Portal, AZ
  • Average wind speed in September: 7.7mph

The windiest month (with the highest average wind speed) is April (11.1mph).
The calmest month (with the lowest average wind speed) is January (7.1mph).

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Average humidity in September
Portal, AZ

Average humidity in September - Portal, AZ
  • Average humidity in September: 43%

The month with the highest relative humidity is December (51%).
The month with the lowest relative humidity is May (21%).

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Average rainfall in September
Portal, AZ

Average rainfall in September - Portal, AZ
  • Average rainfall in September: 1.22"

The wettest month (with the highest rainfall) is July (1.81").
The driest month (with the least rainfall) is April (0.12").

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Average rainfall days in September
Portal, AZ

Average rainfall days in September - Portal, AZ
  • Average rainfall days in September: 9.5 days

The month with the highest number of rainy days is July (15 days).
The month with the least rainy days is May (2.1 days).

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Average snowfall in September
Portal, AZ

Average snowfall in September - Portal, AZ
  • Average snowfall in September: 0"

The month with the highest snowfall is December (0.79").
The months with the least snowfall are April, May, June, July, August, September and October (0").

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Average snowfall days in September
Portal, AZ

Average snowfall days in September - Portal, AZ
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is December (1.5 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).

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Average daylight in September /
Average sunshine in September
Portal, AZ

Average daylight in September / Average sunshine in September - Portal, AZ
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 12min).
The month with the shortest days is December (Average daylight: 10h and 6min).

  • Average sunshine in September: 10h and 4min

The month with the most sunshine is June (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 7h and 0min).

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Average sunshine days in September
Portal, AZ

Average sunshine days in September - Portal, AZ
  • Average sunshine days in September: 16 days

The month with the most sunshine days is May (28.5 days).
The month with the least sunshine days is July (9.9 days).

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Average UV index in September
Portal, AZ

Average UV index in September - Portal, AZ
  • Average UV index in September: 6

The months with the highest UV index are May, June, July and August (UV index 7).
The month with the lowest UV index is December (UV index 2).

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Average cloud cover in September
Portal, AZ

Average cloud cover in September - Portal, AZ
  • Average cloud cover in September: 16

The months with the most cloud cover are July and December (Cloud cover 20).
The month with the least cloud cover is May (Cloud cover 8).

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Average visibility in September
Portal, AZ

Average visibility in September - Portal, AZ
  • 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).

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Portal, Arizona, USA

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