Opelousas weather in September

In September, Opelousas sees average daytime highs of 88°F and overnight lows near 70°F, with 3.9 in of rain across 10.7 wet days and about 12.2 hours of daylight. It is the 4th-warmest and 11th-wettest month of the year here.

Highs ease over the month, from about 90°F in the first days to 86°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 Opelousas's 3rd-clearest and 9th-windiest month. For the whole year in context, see Opelousas's year-round climate.

Daytime high
88°
4th warmest
Overnight low
70°
9th coldest
Rainfall
3.9 in
10.7 wet days
Daylight
12 h 12 min
5:57 AM – 6:08 PM
Cloud cover
50%
3rd clearest
Wind
6 mph
9th windiest
Solar energy
5.02 kWh/m²
Travel score
4.5
out of 10

Opelousas is parish seat of St. Landry Parish, Louisiana, United States.

Founded
1720

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 90°F in the first days to 86°F by the end.

A typical September day in Opelousas reaches about 88°F in the afternoon and slips back to 70°F overnight — a 18°F spread between the day's warmth and the night's chill. On most days the high lands between 81°F and 94°F. Set against its neighbours, September runs about 3°F cooler than August and about 8°F warmer than October.

60°80°100°151015202530
Avg high (°F)Avg low (°F)
19073
29073
39072
49072
59072
69072
78972
88972
98971
108971
118971
128971
138971
148971
158870
168870
178870
188869
198869
208769
218769
228768
238768
248768
258667
268667
278667
288566
298566
308565

How September really feels in Opelousas

Once humidity and wind are folded in, September averages 21 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
21
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.

Opelousas weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan61° / 43°5.19.610.25.2
Feb65° / 46°4.39.210.95.9
Mar71° / 52°4.49.911.86.7
Apr78° / 58°4.59.212.76.9
May85° / 66°4.19.613.55.4
Jun90° / 73°4.713.813.93.7
Jul91° / 74°5.117.213.83.1
Aug91° / 74°4.915.413.13.1
Sep88° / 70°3.910.712.24.5
Oct80° / 60°3.97.411.37.0
Nov70° / 50°3.68.310.57.0
Dec63° / 45°4.89.310.15.7

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 18% of September, with mostly cloudy or overcast conditions the remaining 39%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15149
25149
35347
45347
55446
65446
75644
85743
95743
105842
115941
126040
136040
146139
156139
166139
176238
186238
196238
206337
216337
226436
236535
246634
256634
266733
276733
286832
296832
306832

Chance of precipitation in September

Any precipitation

Opelousas gets around 3.9 in of rain over 10.7 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 36% and peaks near 47% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
147
246
346
445
544
643
742
841
940
1039
1138
1238
1337
1437
1536
1635
1735
1834
1933
2033
2132
2231
2330
2429
2529
2628
2727
2826
2925
3025

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 44% of days. Sticky, muggy-or-worse air turns up on roughly 74% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
1137175913
2148175812
3148175911
4158185810
5258185710
626918569
726919559
827920548
927920548
1027921547
1138921527
1238922517
13381023506
14481023496
15481024476
16481125466
17581125446
18681226426
19781226406
20881326386
211081327376
221181427356
231381427336
241481527315
251681527305
261781626284
271891626274
281991626264
292091626253
3021101626243

Wind in September

Winds average 6 mph in September.

Across September, daily wind ranges from about 5 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

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 5:49 AM to 6:05 AM, and sunset from 6:28 PM to 5:50 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.65:496:28
212.65:496:26
312.65:506:25
412.65:506:24
512.55:516:22
612.55:516:21
712.55:526:20
812.45:536:19
912.45:536:17
1012.45:546:16
1112.35:546:15
1212.35:556:13
1312.35:556:12
1412.25:566:11
1512.25:576:09
1612.25:576:08
1712.25:586:07
1812.15:586:05
1912.15:596:04
2012.15:596:03
2112.06:006:02
2212.06:016:00
2312.06:015:59
2411.96:025:58
2511.96:025:56
2611.96:035:55
2711.86:045:54
2811.86:045:52
2911.86:055:51
3011.76:055:50

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.02 kWh/m².

For context, solar energy here swings from a low near 2.62 kWh/m² to a high of 6.16 kWh/m² in May across the year — September's 5.02 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.3Bright
25.2Bright
35.2Bright
45.2Bright
55.2Bright
65.2Bright
75.2Bright
85.1Bright
95.1Bright
105.1Bright
115.1Bright
125.1Bright
135.0Bright
145.0Bright
155.0Bright
165.0Bright
175.0Bright
184.9Bright
194.9Bright
204.9Bright
214.9Bright
224.9Bright
234.9Bright
244.9Bright
254.8Bright
264.8Bright
274.8Bright
284.8Bright
294.8Bright
304.8Bright
Planning a trip in September

Is September a good time to visit Opelousas?

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

4.5
Sightseeing
9th-best month of the year
6.6
Beach & pool
3rd-best month of the year

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

What to pack for Opelousas in September

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

In September, Opelousas sees daytime highs around 88°F and nights near 70°F. Pack light clothes. Worth having: rain gear and sun protection. About 11 days see rain.

light clothesrain gearsun protection

UV index in Opelousas 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 Opelousas peaks around July 13 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 4 (moderate).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highVery highExtremeVery highHighModerateJul 13UV 10Dec 20UV 4
UV index (midday)Level
Jan4Moderate
Feb6High
Mar7High
Apr10Extreme
May10Very high
Jun10Very high
Jul10Extreme
Aug9Very high
Sep8Very high
Oct6High
Nov5Moderate
Dec4Moderate

Air quality in Opelousas 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 Opelousas is worst in July — around 24 µg/m³ PM2.5 (moderate), about 2.7× the cleanest month (January, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1624 µg/m³Jan 139 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb10Good
Mar12Good
Apr12Good
May16Moderate
Jun20Moderate
Jul24Moderate
Aug19Moderate
Sep15Moderate
Oct11Good
Nov10Good
Dec9Good
Location & terrain

Where is Opelousas?

Opelousas sits at 30.5°N, 92.1°W, 66 ft above sea level, in United States. The nearest listed city is Lafayette, 22 mi away.

Topography around Opelousas

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

Within 2 miles, the terrain around Opelousas has only modest variations in elevation — a maximum elevation change of 98 ft around an average of 72 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 131 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 449 ft.

The land around Opelousas is covered by trees (46%) and grassland (32%) within 2 miles, trees (38%), grassland (34%) and cropland (25%) within 10 miles, and trees (50%) and cropland (29%) within 50 miles.

2 miles
98 ft
10 miles
131 ft
50 miles
449 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Lafayette 22 mi · New Iberia 40 mi · Baton Rouge 53 mi · Zachary 55 mi · Alexandria 58 mi · Central 62 mi · Shenandoah 65 mi · Prairieville 68 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 Opelousas (30.5335°, -92.0815°, elevation 66 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. 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).