September weather forecast
Roswell, GA

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A breathtaking nature scene in the Blue Wall spot with the Old Mills State Park in Roswell, Georgia
A breathtaking nature scene in the Blue Wall spot with the Old Mills State Park in Roswell, Georgia

Weather in September

Roswell in September transitions into autumn, offering a more pleasant weather condition. The average high temperature further descends to 83.8°F (28.8°C), marking the end of intense summer heat. Autumnal gold and red hues begin to paint the city trees. The rainfall drops to 2.8" (71mm), a sizeable reduction since August. Although afternoons can be slightly hot, the evenings bring a cool and comforting breeze.

Temperature

The shift from August to September in Roswell, Georgia, includes a minor decrease in the average high-temperature, lightly dropping from a hot 89.4°F (31.9°C) to a warm 83.8°F (28.8°C). Roswell's temperature in September lowers to a consistent average of 65.3°F (18.5°C) during the nights.

Heat index

The heat index value for September is computed to be a tropical 89.6°F (32°C). If one sustains activity during exposure, it could lead to a sense of fatigue, with a chance of heat cramps.
Note that heat index values are valued for light wind and location in the shade. Direct sunshine exposure could raise heat index values by as much as 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. The impression of weather on a person can be swayed by additional aspects, including metabolic variations, pregnancy, and activity levels. With direct sunlight, be aware that it might enhance the heat sensation, raising the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. Youngsters are usually more at risk than adults, considering they sweat less. Additionally, their high skin surface area compared to their little bodies and their high heat production due to activity increases their risk.

Humidity

The average relative humidity in September is 69%.

Rainfall

In Roswell, in September, it is raining for 13.1 days, with typically 2.8" (71mm) of accumulated precipitation. Throughout the year, there are 183.1 rainfall days, and 45.12" (1146mm) of precipitation is accumulated.

Snowfall

April through October are months without snowfall.

Daylight

In September, the average length of the day in Roswell is 12h and 22min.
On the first day of September, sunrise is at 7:11 am and sunset at 8:02 pm. On the last day of the month, sunrise is at 7:31 am and sunset at 7:22 pm EDT.

Sunshine

In September, the average sunshine is 8.5h.

UV index

In Roswell, Georgia, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the average person.
Note: The daily high UV index of 5 in September translates into this advice:
Act with care - The need to guard against sun damage is communicated. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
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Frequently asked questions

How hot is it in Roswell in September?

Roswell in September has an average high-temperature of 83.8°F (28.8°C) and an average low-temperature of 65.3°F (18.5°C). In September, the average heat index (a.k.a. 'feels like', 'real feel'), which represents the influence of relative humidity on air temperature, is computed to be 89.6°F (32°C).

What is the average humidity in September in Roswell?

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

How many days does it rain in September in Roswell?

In Roswell, Georgia, during September, the rain falls for 13.1 days and regularly aggregates up to 2.8" (71mm) of precipitation.

When it does not snow in Roswell?

In Roswell, snow does not fall in April through October.

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

In Roswell, Georgia, the average day length in September is 12h and 22min.

When are sunrise and sunset in September in Roswell?

On the first day of September, sunrise is at 7:11 am and sunset at 8:02 pm. On the last day of the month, sunrise is at 7:31 am and sunset at 7:22 pm EDT.

How many hours of sunshine does Roswell have in September?

In September, the average sunshine duration is 8.5h.

What is the UV index intensity in September in Roswell?

In Roswell, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate vulnerability from exposure to the Sun's 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
Roswell, GA

Average temperature in September - Roswell, GA
  • Average high temperature in September: 83.8°F

The warmest month (with the highest average high temperature) is July (90.3°F).
The month with the lowest average high temperature is January (49.3°F).

  • Average low temperature in September: 65.3°F

The month with the highest average low temperature is July (71.2°F).
The coldest month (with the lowest average low temperature) is January (34.2°F).

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Average pressure in September
Roswell, GA

Average pressure in September - Roswell, GA
  • Average pressure in September: 30.03"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.99"Hg).

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Average wind speed in September
Roswell, GA

Average wind speed in September - Roswell, GA
  • Average wind speed in September: 5mph

The windiest month (with the highest average wind speed) is January (8mph).
The calmest month (with the lowest average wind speed) is August (4.6mph).

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Average humidity in September
Roswell, GA

Average humidity in September - Roswell, GA
  • Average humidity in September: 69%

The month with the highest relative humidity is December (77%).
The months with the lowest relative humidity are July and August (68%).

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Average rainfall in September
Roswell, GA

Average rainfall in September - Roswell, GA
  • Average rainfall in September: 2.8"

The wettest month (with the highest rainfall) is August (5.55").
The driest month (with the least rainfall) is October (2.36").

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Average rainfall days in September
Roswell, GA

Average rainfall days in September - Roswell, GA
  • Average rainfall days in September: 13.1 days

The month with the highest number of rainy days is July (20.8 days).
The months with the least rainy days are October and November (10.3 days).

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Average snowfall in September
Roswell, GA

Average snowfall in September - Roswell, GA
  • Average snowfall in September: 0"

The month with the highest snowfall is January (1.18").
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
Roswell, GA

Average snowfall days in September - Roswell, GA
  • Average snowfall days in September: 0 days

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

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Average daylight in September /
Average sunshine in September
Roswell, GA

Average daylight in September / Average sunshine in September - Roswell, GA
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).

  • Average sunshine in September: 8h and 3min

The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is December (Average sunshine: 5h and 0min).

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Average sunshine days in September
Roswell, GA

Average sunshine days in September - Roswell, GA
  • Average sunshine days in September: 15 days

The month with the most sunshine days is October (19.1 days).
The month with the least sunshine days is July (8 days).

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Average UV index in September
Roswell, GA

Average UV index in September - Roswell, GA
  • Average UV index in September: 5

The months with the highest UV index are May, June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 2).

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Average cloud cover in September
Roswell, GA

Average cloud cover in September - Roswell, GA
  • Average cloud cover in September: 32

The months with the most cloud cover are February and December (Cloud cover 47).
The month with the least cloud cover is June (Cloud cover 31).

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Average visibility in September
Roswell, GA

Average visibility in September - Roswell, GA
  • 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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Roswell, Georgia, USA

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