September weather forecastWestlyn, TN
September
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.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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: 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: 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: 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: 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: 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: 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: 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: 12h and 24min
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 42min
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: 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: 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: 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: 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).
