La Rochelle weather in September

In September, La Rochelle sees average daytime highs of 21°C and overnight lows near 15°C, with 55 mm of rain across 8 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 8th-wettest month of the year here.

Highs ease over the month, from about 22°C in the first days to 20°C by the end. The sky is clear or mostly clear about 35% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 12 min at the start of September to 11 h 30 min by month's end. Set against the rest of the year, September is La Rochelle's 3rd-clearest and 10th-windiest month. For the whole year in context, see La Rochelle's year-round climate.

Daytime high
21°
3rd warmest
Overnight low
15°
9th coldest
Rainfall
55 mm
8 wet days
Daylight
12 h 18 min
6:49 AM – 7:09 PM
Cloud cover
52%
3rd clearest
Wind
15 km/h
10th windiest
Solar energy
4.1 kWh/m²
Travel score
6.8
out of 10

La Rochelle is French commune and prefecture of Charente-Maritime, New Aquitaine.

Air quality
Good
PM2.5 9.1 µg/m³ · 2019
Density
2,702/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 22°C in the first days to 20°C by the end.

A typical September day in La Rochelle reaches about 21°C in the afternoon and slips back to 15°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 25°C. Set against its neighbours, September runs about 2°C cooler than August and about 4°C warmer than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12316
22216
32216
42215
52215
62215
72215
82215
92215
102215
112215
122115
132115
142115
152114
162114
172114
182114
192114
202114
212014
222014
232014
242014
252014
262014
272014
282014
291913
301913

La Rochelle weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan / 7711.98.81.9
Feb10° / 589.7102.2
Mar13° / 541011.63.5
Apr15° / 579.813.34.5
May18° / 12°5710.214.75.8
Jun21° / 15°478.415.56.7
Jul23° / 17°367.115.27.5
Aug23° / 17°427.2147.6
Sep21° / 15°55812.36.8
Oct17° / 12°8712.310.75.2
Nov13° / 9212.89.23.3
Dec10° / 8712.88.52.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 21% of September, with mostly cloudy or overcast conditions the remaining 45%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16040
26040
36040
46040
56040
66040
75941
85941
95842
105842
115743
125743
135743
145644
155644
165644
175545
185446
195446
205446
215347
225347
235248
245248
255248
265149
275050
284852
294753
304753

Chance of precipitation in September

Any precipitation

La Rochelle gets around 55 mm of rain over 8 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 28% and peaks near 35% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
121
221
321
421
522
622
723
823
924
1025
1125
1226
1326
1427
1528
1628
1728
1829
1929
2030
2130
2231
2331
2432
2532
2633
2733
2834
2935
3035

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the dry band about 41% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
13040246
23140246
33240235
43340234
53440224
63540224
73639223
83639213
93739213
103839212
113938212
123938212
134037212
144137211
154236211
164336201
174436201
184535191
194536191
204636180
214636180
224636170
234736170
244736170
254736170
264836160
274836160
284936160
295035150
305135140

Wind in September

Winds average 15 km/h in September.

Across September, daily wind ranges from about 15 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
115light breeze
215light breeze
315light breeze
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1015light breeze
1115light breeze
1215light breeze
1315light breeze
1415light breeze
1515light breeze
1615light breeze
1715light breeze
1815light breeze
1915light breeze
2015light breeze
2115light breeze
2215light breeze
2315light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 12 min at the start of September to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 102 minutes over September. Sunrise moves from 6:30 AM to 7:08 AM, and sunset from 7:39 PM to 6:40 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.26:307:39
213.16:317:37
313.06:327:35
413.06:347:33
512.96:357:31
612.96:367:29
712.86:387:27
812.86:397:25
912.76:407:23
1012.76:417:21
1112.66:437:19
1212.56:447:17
1312.56:457:15
1412.46:477:13
1512.46:487:11
1612.36:497:09
1712.36:517:07
1812.26:527:04
1912.26:537:02
2012.16:557:00
2112.06:566:58
2212.06:576:56
2311.96:586:54
2411.97:006:52
2511.87:016:50
2611.87:026:48
2711.77:046:46
2811.77:056:44
2911.67:066:42
3011.57:086:40

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.1 kWh/m².

For context, solar energy here swings from a low near 1.08 kWh/m² to a high of 6.19 kWh/m² in June across the year — September's 4.1 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.7Bright
44.7Bright
54.6Bright
64.6Bright
74.5Bright
84.5Bright
94.4Bright
104.4Bright
114.3Bright
124.3Bright
134.2Bright
144.2Bright
154.1Bright
164.0Bright
174.0Bright
183.9Moderate
193.9Moderate
203.8Moderate
213.8Moderate
223.7Moderate
233.6Moderate
243.6Moderate
253.5Moderate
263.5Moderate
273.4Moderate
283.3Moderate
293.3Moderate
303.2Moderate
Planning a trip in September

Is September a good time to visit La Rochelle?

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

6.8
Sightseeing
3rd-best month of the year
4.2
Beach & pool
3rd-best month of the year

September is a reasonable time to visit La Rochelle for sightseeing.

What to pack for La Rochelle in September

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

In September, La Rochelle sees daytime highs around 21°C and nights near 15°C. Worth packing: rain gear. About 8 days see rain.

rain gear

Sea temperature near La Rochelle in September

The nearest coast averages about 19°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 18 km away) is warmest in August at about 20°C and coldest in February near 10°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

10°15°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°C)Comfort
Jan10Bracing
Feb10Bracing
Mar10Bracing
Apr12Bracing
May15Bracing
Jun18Cool
Jul19Cool
Aug20Refreshing
Sep19Cool
Oct17Cool
Nov14Bracing
Dec12Bracing

UV index in La Rochelle in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in La Rochelle peaks around July 20 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highModerateLowJul 20UV 8Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr6High
May6High
Jun7High
Jul8Very high
Aug7Very high
Sep5Moderate
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is La Rochelle?

La Rochelle sits at 46.2°N, 1.2°W, 13 m above sea level, in France. The nearest listed city is Rochefort, 28 km away.

Topography around La Rochelle

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of La Rochelle.

Within 3 km, the terrain around La Rochelle has only modest variations in elevation — a maximum elevation change of 31 m around an average of 11 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 59 m; within 80 km, significant variations in elevation — a maximum elevation change of 305 m.

The land around La Rochelle is covered by artificial surfaces (56%) within 3 km, water (48%) and cropland (29%) within 16 km, and cropland (40%) and water (28%) within 80 km.

3 km
31 m
16 km
59 m
80 km
305 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Rochefort 28 km · Fontenay-le-Comte 43 km · Niort 56 km · La Roche-sur-Yon 60 km · Royan 60 km · Saintes 61 km · Les Sables-d'Olonne 61 km · Les Herbiers 79 km

France travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / E
230 V · 50 Hz
Prices
≈ 77% of US
price level, 2025
GDP per capita
$48,986
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1.3
per 100k, 2023
Road deaths
5.1
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 539
Religion
Roman Catholic 47%none 33%Muslim 4%Protestant 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 La Rochelle (46.1631°, -1.1522°, elevation 13 m), 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. 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).