Louisville, KY weather in September
In September, Louisville sees highs around 82°F and lows around 62°F: warm, with some rain. Rain falls on about 8 days.
- Normal high
- 82°F
- Normal low
- 62°F
- Wet days
- 8
- 3.7 in total
- Muggy days
- 7
- dew point 65°F+
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 87°F | 77°F |
| Normal low | 67°F | 56°F |
| Chance of a wet day | 26% | 26% |
| Sunrise / sunset | 7:12 am / 8:12 pm | 7:37 am / 7:27 pm |
| Daylight | 13.0 h | 11.8 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Eastern Time).
A typical September day
- 6 am63°Fdew point 58°F
- 9 am69°Fdew point 59°F
- Noon77°Fdew point 59°F
- 3 pm80°Fdew point 58°F
- 6 pm78°Fdew point 58°F
- 9 pm72°Fdew point 59°F
NOAA hourly normals (local standard time) from Louisville Intl Airport (5 mi away); average wind 6 mph; clear or few clouds in 59% of daytime hours, mostly cloudy or overcast in 32%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F9 of 30
- Hot dayshigh 90°F or more6 of 30
- Muggy daysdaily mean dew point 65°F or more7 of 30
- Wet daysat least 0.01 in of rain or melted snow8 of 30
- Notable rainat least 0.10 in5 of 30
- Freezing nightslow 32°F or below0 of 30
- Snow on the groundsnow depth 1 in or more0 of 30
Average days per September, counted from daily records for each year 1991-2020.
Rain in September
Normal precipitation is 3.7 in; a dry September brings about 1.4 in and a wet one about 5.6 in (25th and 75th percentiles). About 2 days bring half an inch or more, and about 1 an inch or more.
How September varies from year to year
- Warmest September, 1991-20202019: average high 91°F
- Coolest September2006: average high 75°F
- Wettest September2018: 10.9 in
- Driest September2019: 0.04 in
- Highest reading102°F (September 3, 2011)
- Lowest reading37°F (September 30, 1993)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
September compared with August and October
| August | September | October | |
|---|---|---|---|
| Normal high | 88°F | 82°F | 71°F |
| Normal low | 70°F | 62°F | 50°F |
| Wet days | 8 | 8 | 8 |
| Comfortable days | 1 | 9 | 16 |
| Daylight | 13.6 h | 12.4 h | 11.2 h |
Highs change by -6°F from August and -11°F into October.
Nearby alternatives in September
- Cooler: Fishers, IN125 mi · high 77°F · 9 wet days
How Louisville ranks in September
- Normal high178th warmest of 378 cities; 2nd of 3 in Kentucky
- Wet days193rd driest of 378
- Comfortable days166th most of 342
Heating and cooling
September has 22 heating degree days and 233 cooling degree days (base 65°F), 4% of the year's total heating and cooling demand.
Questions
How hot is Louisville in September?
The normal high is 82°F and the normal low is 62°F. From 1991 to 2020 the hottest September reading was 102°F (September 3, 2011).
Does it rain a lot in Louisville in September?
About 8 days in September have at least 0.01 in of precipitation, and the normal total is 3.7 in. The wettest September in 1991-2020 was in 2018 (10.9 in); the driest was in 2019 (0.04 in).
Is September a good time to visit Louisville?
September ranks 4th of 12 months on our comfort score for Louisville (58 out of 100). It has about 9 comfortable days and about 6 days at 90°F or hotter. The best months are April, May and October.
Where the numbers come from
- Temperature, rain, snowfall, snow depth, frost dates and humidity and wind by hour: Louisville Intl Airport (USW00093821), 5.0 mi WNW of the city center, 488 ft . NOAA normals and daily records, 1991-2020.
- Cloud cover: Louisville Bowman Fld (USW00013810), 4.3 mi N of the city center, 540 ft . NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Louisville Intl-Standiford Field Airport (724230-93821), 4.5 mi W of the city center, 480 ft . Hourly observations, 1991-2020.