September weather forecastLouisville, TN
September
Weather in September
September, the first month of the autumn in Louisville, is still a warm month, with temperature in the range of an average high of 81.1°F (27.3°C) and an average low of 59.9°F (15.5°C).Temperature
With the commencement of September, Louisville records a moderate temperature decline, with the average high easing from August's tropical 86.7°F (30.4°C) to a moderately hot 81.1°F (27.3°C). In Louisville, September is marked by an average low-temperature of 59.9°F (15.5°C).Heat index
The heat index for September is estimated at a tropical 86°F (30°C). With prolonged exposure and constant activity, one might feel exhausted and experience heat cramps.Take into consideration that the heat index values are calculated for shade and light wind conditions. Direct exposure to sunlight could raise the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', quantifies the warmth felt when relative humidity is considered. The impact of weather on an individual can be subjective, affected by the person's activity and heat perception, which can vary due to elements including wind, clothing, and metabolic differences. Sunshine, when direct, has the potential to intensify weather effects, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to children. Youngsters generally face more threats than adults given their lesser ability to sweat. Coupled with their larger skin surface relative to their small bodies and higher heat production due to their activities, they are more endangered.
Humidity
In September, the average relative humidity is 74%.Rainfall
September is the month with the least rainfall in Louisville. Rain falls for 10.6 days and accumulates 0.94" (24mm) of precipitation.Snowfall
In Louisville, snow does not fall in April through September.Daylight
The average length of the day in September is 12h and 23min.On the first day of September, 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.
Sunshine
The average sunshine in September is 8.7h.UV index
In Louisville, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: A typical high UV index of 5 in September suggests 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. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Louisville, TN
- Average high temperature in September: 81.1°F
The warmest month (with the highest average high temperature) is July (87.6°F).
The month with the lowest average high temperature is January (44.8°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (65.5°F).
The coldest month (with the lowest average low temperature) is January (29.5°F).
Average pressure in September
Louisville, 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
Louisville, TN
- Average wind speed in September: 3.8mph
The windiest month (with the highest average wind speed) is April (5.9mph).
The calmest month (with the lowest average wind speed) is August (3.6mph).
Average humidity in September
Louisville, 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
Louisville, TN
- Average rainfall in September: 0.94"
The wettest month (with the highest rainfall) is July (2.2").
The driest month (with the least rainfall) is September (0.94").
Average rainfall days in September
Louisville, TN
- Average rainfall days in September: 10.6 days
The month with the highest number of rainy days is July (16.3 days).
The month with the least rainy days is November (8.7 days).
Average snowfall in September
Louisville, TN
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.98").
The months with the least snowfall are April, May, June, July, August and September (0").
Average snowfall days in September
Louisville, TN
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (5.4 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
Louisville, TN
- Average daylight in September: 12h and 24min
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 48min).
- Average sunshine in September: 8h and 42min
The month with the most sunshine is June (Average sunshine: 10h and 48min).
The month with the least sunshine is January (Average sunshine: 5h and 6min).
Average sunshine days in September
Louisville, TN
- Average sunshine days in September: 17.1 days
The month with the most sunshine days is November (19.3 days).
The months with the least sunshine days are February and July (12.5 days).
Average UV index in September
Louisville, 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
Louisville, TN
- Average cloud cover in September: 30
The month with the most cloud cover is February (Cloud cover 52).
The month with the least cloud cover is June (Cloud cover 27).
Average visibility in September
Louisville, 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).
