September weather forecast
Louisville, KY

englishespañol中文
Share
Louisville city at dusk, Kentucky
Louisville city at dusk, Kentucky

Weather in September

September brings with it the first whispers of autumn. The significant drop in temperature to a high of 79.3°F (26.3°C) adds a cool undertone to the crisp air. Days become shorter, with daylight hours receding to 12.4. Rainfall falls slightly to 1.06" (27mm), marking the onset of the drier season. While noticeable, the changes ushered in by September are subtle, maintaining an easy transition from the heat of summer.

Temperature

With the onset of September, Louisville's average high-temperature slightly adjusts, moderately receding from August's warm 85.6°F (29.8°C) to a still moderately hot 79.3°F (26.3°C). An average nighttime temperature of 60.1°F (15.6°C) is witnessed in Louisville, Kentucky throughout September.

Humidity

In September, the average relative humidity in Louisville is 74%.

Rainfall

The months with the least rainfall in Louisville, Kentucky, are January and September Rain falls for 12.4 days and accumulates 1.06" (27mm) of rain.

Snowfall

May through October are months without snowfall.

Daylight

The average length of the day in September is 12h and 25min.
On the first day of the month, sunrise is at 7:13 am and sunset at 8:12 pm. On the last day of September, in Louisville, sunrise is at 7:38 am and sunset at 7:27 pm EDT.

Sunshine

The average sunshine in September is 8.4h.

UV index

In September, the average daily maximum UV index in Louisville is 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the average person.
Note: In September, the maximum UV index of 5 transforms into these recommendations:
Take precautions. Light skin individuals may get burned in less than 30 minutes. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.

Frequently asked questions

What is the usual temperature for Louisville in September?

The high-temperature, in September, in Louisville, records 79.3°F (26.3°C), while the low-temperature is 60.1°F (15.6°C). The average heat index (a.k.a. 'real feel', 'feels like'), which combines air temperature and relative humidity, in August is calculated to be 95°F (35°C).

What is the average humidity in September in Louisville?

In September, the average relative humidity is 74%.

What is the driest month in Louisville?

January and September are months with the least rain in Louisville when the rain falls for 12.4 days and typically aggregates up to 1.06" (27mm) of rain.

How much does it rain in Louisville in September?

In Louisville, Kentucky, in September, it is raining for 12.4 days, with typically 1.06" (27mm) of accumulated precipitation.

When it does not snow in Louisville?

May through October are months without snowfall in Louisville, Kentucky.

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

In September, the average day length in Louisville is 12h and 25min.

What time are sunrise and sunset in September in Louisville?

In September, on the first day of the month, sunrise is at 7:13 am and sunset at 8:12 pm. On the last day of the month, in Louisville, Kentucky, sunrise is at 7:38 am and sunset at 7:27 pm EDT.

How many hours of sunshine does Louisville have in September?

The average sunshine duration in September is 8.4h.

How high is the UV index in September in Louisville?

In Louisville, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate vulnerability 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
Louisville, KY

Average temperature in September - Louisville, KY
  • Average high temperature in September: 79.3°F

The warmest month (with the highest average high temperature) is July (87.1°F).
The month with the lowest average high temperature is January (38.8°F).

  • Average low temperature in September: 60.1°F

The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (25.9°F).

Average pressure in September
Louisville, KY

Average pressure in September - Louisville, KY
  • Average pressure in September: 30.03"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).

Average wind speed in September
Louisville, KY

Average wind speed in September - Louisville, KY
  • Average wind speed in September: 5.3mph

The windiest month (with the highest average wind speed) is January (7.8mph).
The calmest months (with the lowest average wind speed) are July and August (4.9mph).

Average humidity in September
Louisville, KY

Average humidity in September - Louisville, KY
  • Average humidity in September: 74%

The months with the highest relative humidity are February and December (80%).
The months with the lowest relative humidity are August and October (73%).

Average rainfall in September
Louisville, KY

Average rainfall in September - Louisville, KY
  • Average rainfall in September: 1.06"

The wettest months (with the highest rainfall) are May and July (1.89").
The driest months (with the least rainfall) are January and September (1.06").

Average rainfall days in September
Louisville, KY

Average rainfall days in September - Louisville, KY
  • Average rainfall days in September: 12.4 days

The month with the highest number of rainy days is May (16 days).
The month with the least rainy days is February (8.9 days).

Average snowfall in September
Louisville, KY

Average snowfall in September - Louisville, KY
  • Average snowfall in September: 0"

The month with the highest snowfall is February (1.06").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Louisville, KY

Average snowfall days in September - Louisville, KY
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (7.3 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, KY

Average daylight in September / Average sunshine in September - Louisville, KY
  • Average daylight in September: 12h and 2min

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

  • Average sunshine in September: 8h and 2min

The months with the most sunshine are June and July (Average sunshine: 10h and 24min).
The months with the least sunshine are January and December (Average sunshine: 4h and 24min).

Average sunshine days in September
Louisville, KY

Average sunshine days in September - Louisville, KY
  • Average sunshine days in September: 14.8 days

The month with the most sunshine days is November (19.3 days).
The month with the least sunshine days is May (11.7 days).

Average UV index in September
Louisville, KY

Average UV index in September - Louisville, KY
  • 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, November and December (UV index 2).

Average cloud cover in September
Louisville, KY

Average cloud cover in September - Louisville, KY
  • Average cloud cover in September: 32

The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 28).

Average visibility in September
Louisville, KY

Average visibility in September - Louisville, KY
  • Average visibility in September: 6mi

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

Louisville, Kentucky, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location