September weather forecast
Allen, OK

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Allen, Oklahoma, with an average temperature ranging between min 64.6°F (18.1°C) and max 84.4°F (29.1°C).

Temperature

Allen's weather in September involves a mild decrease in the average high-temperature, moving down slightly from August's hot 92.1°F (33.4°C) to a warm 84.4°F (29.1°C). The nighttime temperature in Allen, during September, averages of 64.6°F (18.1°C).

Heat index

The average heat index in September is evaluated at a tropical 91.4°F (33°C). Adopt heightened preventive measures, heat exhaustion and heat cramps are probable. Persistent activity could lead to heatstroke.
Realize that the values for the heat index are set for shaded places and light winds. With direct sunlight, the heat index could increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', is an indicator that blends the effects of temperature and humidity to depict perceived warmth. The effect is experienced differently by individuals, hinging on unique characteristics such as body mass, stature, and level of activity. Taking into account that direct sunlight can boost the heat effect, the heat index may rise by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to children. Children typically face more danger than adults as their sweat production is usually lower. Additionally, the bigger skin surface compared to their small size and the increased heat due to their activeness exacerbate the risk.

Humidity

In Allen, the average relative humidity in September is 69%.

Rainfall

In Allen, during September, the rain falls for 12.5 days and regularly aggregates up to 2.52" (64mm) of precipitation. In Allen, during the entire year, the rain falls for 131 days and collects up to 28.39" (721mm) of precipitation.

Snowfall

May through October are months without snowfall.

Daylight

In Allen, the average length of the day in September is 12h and 23min.
On the first day of September, sunrise is at 6:59 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 7:10 pm CDT.

Sunshine

In September, the average sunshine is 8.6h.

UV index

In September, the average daily maximum UV index is 5. 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: A maximum UV index of 5 in September translates into the following recommendations:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit.
Updated: Jul 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How hot does it get in September?

In Allen, 84.4°F (29.1°C) is the average high-temperature and 64.6°F (18.1°C) is the average low-temperature during September. In September, the average heat index (a.k.a. 'apparent temperature', 'real feel'), which factors the actual air temperature with the relative humidity, is evaluated at 91.4°F (33°C).

What is the average humidity in September?

In Allen, the average relative humidity in September is 69%.

How much does it rain in September?

In Allen, in September, it is raining for 12.5 days, with typically 2.52" (64mm) of accumulated precipitation.

When it does not snow?

May through October are months without snowfall.

How many hours of daylight does Allen have in September?

The average day length in September is 12h and 23min.

When is the sunrise / sunset in September?

On the first day of September, sunrise is at 6:59 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 7:10 pm CDT.

How many hours of sunshine does Allen have in September?

In September, the average sunshine duration is 8.6h.

What is the UV index intensity in September?

In Allen, Oklahoma, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium hazard to health 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
Allen, OK

Average temperature in September - Allen, OK
  • Average high temperature in September: 84.4°F

The warmest month (with the highest average high temperature) is August (92.1°F).
The month with the lowest average high temperature is January (48.7°F).

  • Average low temperature in September: 64.6°F

The month with the highest average low temperature is July (72.3°F).
The coldest month (with the lowest average low temperature) is January (33.3°F).

Average pressure in September
Allen, OK

Average pressure in September - Allen, OK
  • Average pressure in September: 29.98"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
Allen, OK

Average wind speed in September - Allen, OK
  • Average wind speed in September: 7.6mph

The windiest month (with the highest average wind speed) is March (11mph).
The calmest month (with the lowest average wind speed) is July (7.3mph).

Average humidity in September
Allen, OK

Average humidity in September - Allen, OK
  • Average humidity in September: 69%

The month with the highest relative humidity is May (80%).
The month with the lowest relative humidity is August (64%).

Average rainfall in September
Allen, OK

Average rainfall in September - Allen, OK
  • Average rainfall in September: 2.52"

The wettest month (with the highest rainfall) is May (4.33").
The driest month (with the least rainfall) is February (1.42").

Average rainfall days in September
Allen, OK

Average rainfall days in September - Allen, OK
  • Average rainfall days in September: 12.5 days

The month with the highest number of rainy days is May (15.1 days).
The month with the least rainy days is January (6.7 days).

Average snowfall in September
Allen, OK

Average snowfall in September - Allen, OK
  • Average snowfall in September: 0"

The month with the highest snowfall is February (1.54").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Allen, OK

Average snowfall days in September - Allen, OK
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (2.1 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in September /
Average sunshine in September
Allen, OK

Average daylight in September / Average sunshine in September - Allen, OK
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 54min).

  • Average sunshine in September: 8h and 4min

The month with the most sunshine is August (Average sunshine: 11h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).

Average sunshine days in September
Allen, OK

Average sunshine days in September - Allen, OK
  • Average sunshine days in September: 15.5 days

The month with the most sunshine days is January (22.5 days).
The month with the least sunshine days is May (14.5 days).

Average UV index in September
Allen, OK

Average UV index in September - Allen, OK
  • Average UV index in September: 5

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

Average cloud cover in September
Allen, OK

Average cloud cover in September - Allen, OK
  • Average cloud cover in September: 28

The months with the most cloud cover are February and March (Cloud cover 40).
The month with the least cloud cover is August (Cloud cover 20).

Average visibility in September
Allen, OK

Average visibility in September - Allen, OK
  • 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).

Allen, Oklahoma, USA

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