Slidell weather in September: Slidell, Louisiana: normal highs, lows, rain and records for September
Slidell in September has a normal high of 88°F and a normal low of 69°F, a daily mean of 78°F, falling from 90°F on the 1st to 85°F by the 30th. Measurable precipitation falls on 10 days in a normal September, 4.14 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 31°C and low of 20°C, 105 mm of precipitation in September.
- NOAA stationSlidell Airport
- Station IDUSW00053865
- Location30.34°N 89.82°W
- Elevation27 ft (8 m)
- Population28,440
- Jan 62° 41°
- Feb 66° 44°
- Mar 72° 50°
- Apr 78° 56°
- May 85° 64°
- Jun 90° 71°
- Jul 91° 73°
- Aug 91° 73°
- Sep 88° 69°
- Oct 81° 57°
- Nov 71° 47°
- Dec 64° 43°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Slidell in September?
The normal high is 88°F and the normal low 69°F, for a daily mean of 78.2°F. September is 3.9°F cooler than August and 9.3°F warmer than October. September is the 4th warmest month of the year in Slidell and the 9th wettest. Across the month the normal high falls 5°F, from 90°F on September 1 to 85°F on September 30. From one year to the next September's mean temperature typically moves about 1.7°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 77°F and 80°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 41%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 90°F | 72°F | 41% | 26% |
| September 8 | 89°F | 71°F | 37% | 24% |
| September 15 | 88°F | 69°F | 34% | 21% |
| September 22 | 87°F | 67°F | 31% | 18% |
| September 30 | 85°F | 64°F | 27% | 15% |
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 | 90°F | 72°F | 41% | 26% | 12 h 50 min |
| September 2 | 90°F | 72°F | 40% | 26% | 12 h 50 min |
| September 3 | 90°F | 71°F | 40% | 26% | 12 h 40 min |
| September 4 | 90°F | 71°F | 39% | 25% | 12 h 40 min |
| September 5 | 90°F | 71°F | 39% | 25% | 12 h 40 min |
| September 6 | 90°F | 71°F | 38% | 25% | 12 h 40 min |
| September 7 | 90°F | 71°F | 38% | 24% | 12 h 40 min |
| September 8 | 89°F | 71°F | 37% | 24% | 12 h 40 min |
| September 9 | 89°F | 70°F | 37% | 23% | 12 h 30 min |
| September 10 | 89°F | 70°F | 36% | 23% | 12 h 30 min |
| September 11 | 89°F | 70°F | 36% | 22% | 12 h 30 min |
| September 12 | 89°F | 70°F | 35% | 22% | 12 h 30 min |
| September 13 | 89°F | 69°F | 35% | 22% | 12 h 30 min |
| September 14 | 88°F | 69°F | 34% | 21% | 12 h 30 min |
| September 15 | 88°F | 69°F | 34% | 21% | 12 h 20 min |
| September 16 | 88°F | 69°F | 33% | 20% | 12 h 20 min |
| September 17 | 88°F | 68°F | 33% | 20% | 12 h 20 min |
| September 18 | 88°F | 68°F | 32% | 20% | 12 h 20 min |
| September 19 | 88°F | 68°F | 32% | 19% | 12 h 20 min |
| September 20 | 87°F | 68°F | 31% | 19% | 12 h 10 min |
| September 21 | 87°F | 67°F | 31% | 19% | 12 h 10 min |
| September 22 | 87°F | 67°F | 31% | 18% | 12 h 10 min |
| September 23 | 87°F | 67°F | 30% | 18% | 12 h 10 min |
| September 24 | 87°F | 66°F | 30% | 18% | 12 h 10 min |
| September 25 | 86°F | 66°F | 29% | 17% | 12 h 10 min |
| September 26 | 86°F | 66°F | 29% | 17% | 12 h |
| September 27 | 86°F | 65°F | 28% | 16% | 12 h |
| September 28 | 86°F | 65°F | 28% | 16% | 12 h |
| September 29 | 85°F | 65°F | 27% | 16% | 12 h |
| September 30 | 85°F | 64°F | 27% | 15% | 12 h |
- Normal high
- 88°FSeptember average
- Normal low
- 69°FSeptember average
- Precipitation
- 4.14 inmonth total
- Days with precipitation
- 100.01 inch or more
- Days at 90°F or more
- 13
- Daylight
- 12 h 50 min to 12 hSeptember 1 to September 30
- Days at 70°F or more
- 30
- Days at 80°F or more
- 29
- Sunshine
- 83%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00053865; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Slidell in September?
On a given September day the chance of 0.01 inch or more is 34% on average, highest around September 1 (41%). In all, 4.14 in falls on 10 days of a normal September, 1 of them with an inch or more.
In a normal September in Slidell, 13 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00053865.
What are the records for September in Slidell?
The warmest September temperature on this station's record (since 1994) is 99°F, on September 4, 2000; the coldest is 46°F, on September 23, 1999. The wettest September brought 14.28 in (1998).
The September mean against the 1991-2020 normal of 78.2°F: 2021 78.3°F (+0.1), 2022 78.2°F (at normal), 2023 81.3°F (+3.0), 2024 79.7°F (+1.5), 2025 78.2°F (at normal), 2026 80.8°F (+2.6). 4 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 78.3°F | +0.1°F | 6.15 in |
| 2022 | 78.2°F | at normal | 2.43 in |
| 2023 | 81.3°F | +3.0°F | 8.21 in |
| 2024 | 79.7°F | +1.5°F | 9.84 in |
| 2025 | 78.2°F | at normal | 1.33 in |
| 2026 | 80.8°F | +2.6°F | 4.27 in |
Source: records: ACIS, station USW00053865; recent months: ACIS, station USW00053865. Records and recent months use complete months only.
How does September in Slidell compare across Louisiana?
Across the 65 places PlainClimate covers in Louisiana, September normal highs run from 85°F in Boyce to 90°F in Natchitoches; Slidell's is 88°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.