Louisville weather in September: Louisville, Kentucky: normal highs, lows, rain and records for September
Louisville in September has a normal high of 82°F and a normal low of 62°F, a daily mean of 72°F, falling from 87°F on the 1st to 77°F by the 30th. Measurable precipitation falls on 8 days in a normal September, 3.66 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 28°C and low of 17°C, 93 mm of precipitation in September.
- NOAA stationLouisville International Airport
- Station IDUSW00093821
- Location38.18°N 85.74°W
- Elevation488 ft (149 m)
- From the center5 miles
- Population640,796
- Jan 44° 28°
- Feb 48° 31°
- Mar 58° 39°
- Apr 70° 49°
- May 78° 59°
- Jun 86° 67°
- Jul 89° 71°
- Aug 88° 70°
- Sep 82° 62°
- Oct 71° 50°
- Nov 58° 39°
- Dec 47° 32°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Louisville in September?
The normal high is 82°F and the normal low 62°F, for a daily mean of 72.0°F. September is 6.9°F cooler than August and 11.7°F warmer than October. September is the 4th warmest month of the year in Louisville and the 9th wettest. Across the month the normal high falls 10°F, from 87°F on September 1 to 77°F on September 30. From one year to the next September's mean temperature typically moves about 3.1°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 69°F and 75°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 26%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 87°F | 67°F | 26% | 16% |
| September 8 | 85°F | 65°F | 26% | 15% |
| September 15 | 83°F | 62°F | 25% | 15% |
| September 22 | 80°F | 60°F | 26% | 16% |
| September 30 | 77°F | 56°F | 25% | 16% |
Every day of September: normal high, low and chance of precipitation (warmest afternoon September 1, coldest night September 30)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| September 1 | 87°F | 67°F | 26% | 16% | 13 h |
| September 2 | 86°F | 67°F | 26% | 16% | 13 h |
| September 3 | 86°F | 66°F | 26% | 16% | 13 h |
| September 4 | 86°F | 66°F | 26% | 16% | 13 h |
| September 5 | 86°F | 66°F | 26% | 16% | 12 h 50 min |
| September 6 | 85°F | 65°F | 26% | 15% | 12 h 50 min |
| September 7 | 85°F | 65°F | 26% | 15% | 12 h 50 min |
| September 8 | 85°F | 65°F | 26% | 15% | 12 h 50 min |
| September 9 | 85°F | 64°F | 26% | 15% | 12 h 40 min |
| September 10 | 84°F | 64°F | 26% | 15% | 12 h 40 min |
| September 11 | 84°F | 64°F | 26% | 15% | 12 h 40 min |
| September 12 | 84°F | 63°F | 25% | 15% | 12 h 40 min |
| September 13 | 83°F | 63°F | 25% | 15% | 12 h 30 min |
| September 14 | 83°F | 63°F | 25% | 15% | 12 h 30 min |
| September 15 | 83°F | 62°F | 25% | 15% | 12 h 30 min |
| September 16 | 82°F | 62°F | 25% | 15% | 12 h 30 min |
| September 17 | 82°F | 62°F | 25% | 15% | 12 h 20 min |
| September 18 | 82°F | 61°F | 25% | 15% | 12 h 20 min |
| September 19 | 81°F | 61°F | 26% | 16% | 12 h 20 min |
| September 20 | 81°F | 60°F | 26% | 16% | 12 h 20 min |
| September 21 | 81°F | 60°F | 26% | 16% | 12 h 10 min |
| September 22 | 80°F | 60°F | 26% | 16% | 12 h 10 min |
| September 23 | 80°F | 59°F | 26% | 16% | 12 h 10 min |
| September 24 | 79°F | 59°F | 26% | 16% | 12 h 10 min |
| September 25 | 79°F | 58°F | 26% | 16% | 12 h 10 min |
| September 26 | 79°F | 58°F | 26% | 16% | 12 h |
| September 27 | 78°F | 58°F | 26% | 16% | 12 h |
| September 28 | 78°F | 57°F | 26% | 16% | 12 h |
| September 29 | 77°F | 57°F | 25% | 16% | 12 h |
| September 30 | 77°F | 56°F | 25% | 16% | 11 h 50 min |
- Normal high
- 82°FSeptember average
- Normal low
- 62°FSeptember average
- Precipitation
- 3.66 inmonth total
- Days with precipitation
- 80.01 inch or more
- Days at 90°F or more
- 6
- Daylight
- 13 h to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 28
- Days at 80°F or more
- 19
- Sunshine
- 79%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00093821; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Louisville in September?
On a given September day the chance of 0.01 inch or more is 26% on average, highest around September 1 (26%). In all, 3.66 in falls on 8 days of a normal September, 1 of them with an inch or more.
In a normal September in Louisville, 6 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00093821.
How humid and windy is Louisville in September?
At 3 p.m. the normal temperature is 75°F with 46% relative humidity and a dew point of 53°F; at 6 a.m. it is 58°F with 83% humidity. The wind averages 6.4 mph, most often from the west-southwest in the afternoon.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 58°F | 53°F | 83% | 4.9 mph | 58% |
| 9 a.m. | 63°F | 54°F | 72% | 5.9 mph | 53% |
| noon | 72°F | 54°F | 53% | 8.1 mph | – |
| 3 p.m. | 75°F | 53°F | 46% | 8.9 mph | – |
| 6 p.m. | 72°F | 53°F | 50% | 8.2 mph | 45% |
| 9 p.m. | 66°F | 54°F | 65% | 5.6 mph | 63% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00093821. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for September in Louisville?
The warmest September temperature on Louisville's official record (since 1872) is 104°F, on September 6, 1954; the coldest is 33°F, on September 30, 1949. The wettest September brought 10.91 in (2018).
The September mean against the 1991-2020 normal of 72.0°F: 2021 73.4°F (+1.4), 2022 72.0°F (at normal), 2023 74.0°F (+2.0), 2024 75.0°F (+3.0), 2025 73.0°F (+1.0), 2026 77.8°F (+5.8). 5 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 73.4°F | +1.4°F | 4.76 in |
| 2022 | 72.0°F | at normal | 2.04 in |
| 2023 | 74.0°F | +2.0°F | 0.74 in |
| 2024 | 75.0°F | +3.0°F | 6.71 in |
| 2025 | 73.0°F | +1.0°F | 4.17 in |
| 2026 | 77.8°F | +5.8°F | 1.16 in |
Source: records: ACIS, NWS threaded record SDFthr; recent months: ACIS, station USW00093821. Records and recent months use complete months only.
How does September in Louisville compare across Kentucky?
Across the 68 places PlainClimate covers in Kentucky, September normal highs run from 76°F in Olive Hill to 85°F in Eddyville; Louisville's is 82°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Louisville in August88°F by day, 70°F at night
- Louisville in October71°F by day, 50°F at night
- Louisville through the yearEvery month, frost dates, records and recent years
- Kentucky in SeptemberThe statewide normal and the warmest and coolest places
- Eddyville: Kentucky's warmest Septembernormal high 85°F