September weather forecast
Westlyn, TN

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Weather in September

September, the first month of the autumn in Westlyn, is still a warm month, with an average temperature varying between 60.1°F (15.6°C) and 81.3°F (27.4°C).

Temperature

A minor decrease in the average high-temperature is observed during September, shifting from a hot 87.1°F (30.6°C) in August to a warm 81.3°F (27.4°C). In Westlyn, September is marked by an average low-temperature of 60.1°F (15.6°C).

Heat index

For most parts of September, the heat index is estimated at a hot 86°F (30°C). Exhaustion is likely with prolonged exposure and activity. Sustaining activity may result in heat cramps.
Realize that the values for the heat index are set for shaded places and light winds. If directly exposed to the sun, the heat index could rise by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', is a calculation that merges air temperature and relative humidity to depict the sensation of warmth. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. 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 especially vital to children. Young people are generally more susceptible than adults because they perspire less. Furthermore, their proportionally larger skin surface to their petite bodies and the increased heat output from their actions add to the risk.

Humidity

The average relative humidity in September is 74%.

Rainfall

The month with the least rainfall is September, when the rain falls for 12.6 days and typically collects 1.97" (50mm) of precipitation.

Snowfall

May through September are months without snowfall.

Daylight

The average length of the day in September is 12h and 23min.
On the first day of the month, sunrise is at 7:08 am and sunset at 8:03 pm. On the last day of September, in Westlyn, sunrise is at 7:30 am and sunset at 7:20 pm EDT.

Sunshine

In September, the average sunshine is 8.7h.

UV index

In September, the average daily maximum UV index is 5. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for ordinary individuals.
Note: The maximum daily UV index of 5 in September interprets into the following recommendations:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. Around midday, solar radiation is most harmful; hence, exposure should be limited. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Updated: Aug 22, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average September temperature?

During September, Westlyn experiences an average high-temperature of 81.3°F (27.4°C) and a low-temperature of 60.1°F (15.6°C). The average heat index (a.k.a. 'felt air temperature', 'feels like'), which combines relative humidity and air temperature, in September is estimated at 86°F (30°C).

What is the average humidity in September?

The average relative humidity in September is 74%.

What is the driest month?

The month with the least rainfall is September, when the rain falls for 12.6 days and typically collects 1.97" (50mm) of precipitation.

How much does it rain in September?

In Westlyn, during September, the rain falls for 12.6 days and regularly aggregates up to 1.97" (50mm) of precipitation.

When it does not snow?

May through September are months without snowfall.

Does it snow in September?

In Westlyn, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September?

In September, the average day length is 12h and 23min.

What time are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 7:08 am and sunset at 8:03 pm. On the last day of the month, sunrise is at 7:30 am and sunset at 7:20 pm EDT.

How many hours of sunshine does Westlyn have in September?

The average sunshine duration in September is 8.7h.

What is the UV index intensity in September?

In September, the average daily maximum UV index is 5. A UV Index reading of 3 to 5 represents a medium health risk from unsafe 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
Westlyn, TN

Average temperature in September - Westlyn, TN
  • Average high temperature in September: 81.3°F

The warmest month (with the highest average high temperature) is July (87.8°F).
The month with the lowest average high temperature is January (44.8°F).

  • Average low temperature in September: 60.1°F

The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (29.7°F).

Average pressure in September
Westlyn, TN

Average pressure in September - Westlyn, TN
  • Average pressure in September: 30.04"Hg

The months with the highest atmospheric pressure are January and November (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).

Average wind speed in September
Westlyn, TN

Average wind speed in September - Westlyn, TN
  • Average wind speed in September: 3.8mph

The windiest month (with the highest average wind speed) is April (6mph).
The calmest month (with the lowest average wind speed) is August (3.6mph).

Average humidity in September
Westlyn, TN

Average humidity in September - Westlyn, TN
  • Average humidity in September: 74%

The month with the highest relative humidity is December (79%).
The month with the lowest relative humidity is August (72%).

Average rainfall in September
Westlyn, TN

Average rainfall in September - Westlyn, TN
  • Average rainfall in September: 1.97"

The wettest month (with the highest rainfall) is February (4.33").
The driest month (with the least rainfall) is September (1.97").

Average rainfall days in September
Westlyn, TN

Average rainfall days in September - Westlyn, TN
  • Average rainfall days in September: 12.6 days

The month with the highest number of rainy days is July (18.6 days).
The month with the least rainy days is November (10.3 days).

Average snowfall in September
Westlyn, TN

Average snowfall in September - Westlyn, TN
  • Average snowfall in September: 0"

The month with the highest snowfall is February (1.93").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Westlyn, TN

Average snowfall days in September - Westlyn, TN
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (5.5 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Westlyn, TN

Average daylight in September / Average sunshine in September - Westlyn, TN
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 48min).

  • Average sunshine in September: 8h and 4min

The month with the most sunshine is June (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 5h and 6min).

Average sunshine days in September
Westlyn, TN

Average sunshine days in September - Westlyn, TN
  • Average sunshine days in September: 16.2 days

The month with the most sunshine days is November (17.8 days).
The month with the least sunshine days is July (10.3 days).

Average UV index in September
Westlyn, TN

Average UV index in September - Westlyn, TN
  • Average UV index in September: 5

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

Average cloud cover in September
Westlyn, TN

Average cloud cover in September - Westlyn, TN
  • Average cloud cover in September: 30

The month with the most cloud cover is February (Cloud cover 52).
The months with the least cloud cover are June and August (Cloud cover 28).

Average visibility in September
Westlyn, TN

Average visibility in September - Westlyn, TN
  • Average visibility in September: 6mi

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

Westlyn, Tennessee, USA

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