Laplace weather in September

In September, Laplace sees average daytime highs of 85°F and overnight lows near 73°F, with 4.7 in of rain across 12.4 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 87°F in the first days to 83°F by the end. The sky is clear or mostly clear about 43% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 36 min at the start of September to 11 h 42 min by month's end. Set against the rest of the year, September is Laplace's 4th-clearest and 9th-windiest month. For the whole year in context, see Laplace's year-round climate.

Daytime high
85°
4th warmest
Overnight low
73°
9th coldest
Rainfall
4.7 in
12.4 wet days
Daylight
12 h 12 min
5:51 AM – 6:02 PM
Cloud cover
51%
4th clearest
Wind
7 mph
9th windiest
Solar energy
4.84 kWh/m²
Travel score
5.1
out of 10

Laplace is unincorporated suburban community and census-designated place in St. John the Baptist Parish, Louisiana, United States.

Density
523/km²
people per km²

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 87°F in the first days to 83°F by the end.

A typical September day in Laplace reaches about 85°F in the afternoon and slips back to 73°F overnight — a 11°F spread between the day's warmth and the night's chill. On most days the high lands between 80°F and 89°F. Set against its neighbours, September runs about 3°F cooler than August and about 7°F warmer than October.

60°70°80°90°151015202530
Avg high (°F)Avg low (°F)
18776
28776
38776
48775
58675
68675
78675
88675
98675
108675
118674
128674
138574
148574
158574
168574
178573
188573
198573
208473
218473
228472
238472
248372
258371
268371
278371
288370
298270
308270

How September really feels in Laplace

Once humidity and wind are folded in, September averages 19 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
19
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Laplace weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan61° / 47°4.79.710.35.2
Feb65° / 50°4.59.310.95.9
Mar70° / 56°4.59.511.86.7
Apr76° / 62°4.18.912.77.1
May83° / 69°3.99.513.56.1
Jun87° / 75°5.115.213.94.2
Jul88° / 77°5.61913.73.5
Aug88° / 77°5.918.613.13.6
Sep85° / 73°4.712.412.25.1
Oct78° / 64°3.68.211.37.3
Nov70° / 55°3.57.710.57.0
Dec63° / 49°4.09.410.15.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 43% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 16% of September, with mostly cloudy or overcast conditions the remaining 41%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15050
25149
35347
45248
55347
65446
75545
85644
95644
105743
115842
125842
135842
145842
155842
165941
176040
186040
196040
206040
216139
226238
236238
246436
256436
266535
276535
286634
296634
306634

Chance of precipitation in September

Any precipitation

Laplace gets around 4.7 in of rain over 12.4 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 42% and peaks near 52% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
152
251
351
450
549
648
748
847
946
1045
1145
1244
1344
1443
1543
1642
1742
1841
1940
2039
2138
2237
2336
2435
2534
2633
2732
2832
2931
3030

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the oppressive band about 51% of days. Sticky, muggy-or-worse air turns up on roughly 87% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
101295137
2012105235
3012105334
4013105432
5023115331
6023115430
7023115628
8024115627
9024125626
10024125725
11034125724
12035135623
13135135622
14135145522
15135145621
16135145620
17146155420
18246165319
19256165318
20256175317
21367175017
22477184916
23478184814
24589194613
25599194512
266910204412
2771011204211
2881011204110
298111221399
309111321388

Wind in September

Winds average 7 mph in September.

Across September, daily wind ranges from about 6 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 36 min at the start of September to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 54 minutes over September. Sunrise moves from 5:43 AM to 5:59 AM, and sunset from 6:21 PM to 5:44 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.65:436:21
212.65:436:20
312.65:446:18
412.55:446:17
512.55:456:16
612.55:456:15
712.55:466:13
812.45:466:12
912.45:476:11
1012.45:486:09
1112.35:486:08
1212.35:496:07
1312.35:496:06
1412.25:506:04
1512.25:506:03
1612.25:516:02
1712.15:516:00
1812.15:525:59
1912.15:535:58
2012.15:535:56
2112.05:545:55
2212.05:545:54
2312.05:555:52
2411.95:555:51
2511.95:565:50
2611.95:575:49
2711.85:575:47
2811.85:585:46
2911.85:585:45
3011.75:595:44

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.84 kWh/m².

For context, solar energy here swings from a low near 2.69 kWh/m² to a high of 6.15 kWh/m² in May across the year — September's 4.84 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.0Bright
25.0Bright
35.0Bright
45.0Bright
55.0Bright
65.0Bright
75.0Bright
85.0Bright
94.9Bright
104.9Bright
114.9Bright
124.9Bright
134.9Bright
144.8Bright
154.8Bright
164.8Bright
174.8Bright
184.8Bright
194.8Bright
204.8Bright
214.7Bright
224.7Bright
234.7Bright
244.7Bright
254.7Bright
264.7Bright
274.7Bright
284.7Bright
294.7Bright
304.6Bright
Planning a trip in September

Hazard calendar for Laplace

In seasonPeak

In September, Laplace sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

Laplace sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Laplace?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

5.1
Sightseeing
9th-best month of the year
6.6
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Laplace for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Laplace in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Laplace sees daytime highs around 85°F and nights near 73°F. Pack light clothes. Worth having: rain gear and sun protection. About 12 days see rain.

light clothesrain gearsun protection

Sea temperature near Laplace in September

The nearest coast averages about 83°F in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 86°F and coldest in January near 58°F.

It's comfortable for a long swim from Apr 5 to Nov 14 — about 7.4 months when the water holds above 68°F.

60°70°80°90°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°F)Comfort
Jan58Bracing
Feb58Bracing
Mar64Cool
Apr71Refreshing
May78Warm
Jun84Tropical
Jul86Tropical
Aug86Tropical
Sep83Tropical
Oct76Warm
Nov67Cool
Dec61Cool

UV index in Laplace in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Laplace peaks around July 12 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 4 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJul 12UV 10Dec 19UV 4
UV index (midday)Level
Jan4Moderate
Feb6High
Mar7High
Apr10Very high
May10Very high
Jun10Extreme
Jul10Extreme
Aug9Very high
Sep8Very high
Oct6High
Nov5Moderate
Dec4Moderate

Air quality in Laplace in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Laplace is worst in July — around 23 µg/m³ PM2.5 (moderate), about 2.5× the cleanest month (January, 9 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1623 µg/m³Jan 199 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb10Good
Mar11Good
Apr11Good
May15Moderate
Jun20Moderate
Jul23Moderate
Aug19Moderate
Sep14Moderate
Oct12Good
Nov11Good
Dec10Good
Location & terrain

Where is Laplace?

Laplace sits at 30.1°N, 90.5°W, 10 ft above sea level, in United States. The nearest listed city is Kenner, 15 mi away.

Topography around Laplace

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Laplace.

Within 2 miles, the terrain around Laplace has only modest variations in elevation — a maximum elevation change of 72 ft around an average of 13 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 95 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 295 ft.

The land around Laplace is covered by trees (31%), grassland (28%) and artificial surfaces (20%) within 2 miles, trees (46%) and water (27%) within 10 miles, and trees (46%) and water (22%) within 50 miles.

2 miles
72 ft
10 miles
95 ft
50 miles
295 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Kenner 15 mi · Metairie Terrace 20 mi · Metairie 21 mi · New Orleans 25 mi · Marrero 25 mi · Harvey 27 mi · Estelle 27 mi · Gretna 28 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Laplace (30.067°, -90.4815°, elevation 10 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).