Biarritz weather in September

In September, Biarritz sees average daytime highs of 22°C and overnight lows near 16°C, with 88 mm of rain across 11.4 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 9th-wettest month of the year here.

Highs ease over the month, from about 23°C in the first days to 21°C by the end. The sky is clear or mostly clear about 33% of the time in September, and the air most often feels comfortable.

Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Biarritz's 3rd-clearest and 11th-windiest month. For the whole year in context, see Biarritz's year-round climate.

Daytime high
22°
3rd warmest
Overnight low
16°
10th coldest
Rainfall
88 mm
11.4 wet days
Daylight
12 h 18 min
6:52 AM – 7:09 PM
Cloud cover
53%
3rd clearest
Wind
11 km/h
11th windiest
Solar energy
4.27 kWh/m²
Travel score
6.5
out of 10

Biarritz is human settlement in France.

Air quality
Good
PM2.5 6.5 µg/m³ · 2019

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 23°C in the first days to 21°C by the end.

A typical September day in Biarritz reaches about 22°C in the afternoon and slips back to 16°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 27°C. Set against its neighbours, September runs about 2°C cooler than August and about 3°C warmer than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12317
22317
32317
42317
52317
62317
72317
82317
92317
102317
112317
122316
132216
142216
152216
162216
172216
182216
192216
202216
212216
222216
232216
242215
252115
262115
272115
282115
292115
302115

Biarritz weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan12° / 12314.19.12.7
Feb12° / 10612.710.22.9
Mar14° / 9812.811.64.0
Apr16° / 10°10614.213.24.4
May19° / 13°9613.114.55.6
Jun21° / 16°7610.715.26.4
Jul23° / 18°6410.314.97.0
Aug24° / 18°6510.213.87.2
Sep22° / 16°8811.412.36.5
Oct19° / 14°11412.810.85.7
Nov15° / 10°16214.99.53.9
Dec12° / 13414.18.83.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 33% 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 (%)
15842
25941
35941
45941
55941
65842
75842
85842
95743
105743
115743
125644
135644
145644
155545
165545
175347
185347
195347
205347
215347
225347
235347
245248
255149
265149
275050
284951
294951
304753

Chance of precipitation in September

Any precipitation

Biarritz gets around 88 mm of rain over 11.4 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 39% and peaks near 42% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
136
236
336
436
536
636
736
837
937
1038
1138
1239
1339
1440
1540
1640
1740
1841
1941
2041
2141
2241
2341
2441
2541
2641
2741
2841
2941
3042

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the comfortable band about 35% of days. Sticky, muggy-or-worse air turns up on roughly 12% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
172938242
273038232
383138222
493138212
593237202
6103237192
7113337181
8113337171
9123337161
10133437161
11143436151
12153436141
13163435141
14163535131
15173535120
16183634110
17193634100
1821363390
1922373380
2023373280
2124383270
2225383160
2326383150
2426383150
2527383040
2628383040
2729383030
2830382930
2932372830
3033372820

Wind in September

Winds average 11 km/h in September.

Across September, daily wind ranges from about 10 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3012calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 hours at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 84 minutes over September. Sunrise moves from 6:35 AM to 7:08 AM, and sunset from 7:37 PM to 6:43 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.06:357:37
213.06:367:36
312.96:377:34
412.96:387:32
512.86:397:30
612.86:407:28
712.76:417:26
812.76:437:24
912.66:447:23
1012.66:457:21
1112.56:467:19
1212.56:477:17
1312.46:487:15
1412.46:497:13
1512.36:517:11
1612.36:527:09
1712.26:537:07
1812.26:547:06
1912.16:557:04
2012.16:567:02
2112.06:587:00
2212.06:596:58
2311.97:006:56
2411.97:016:54
2511.87:026:52
2611.87:036:50
2711.77:056:49
2811.77:066:47
2911.67:076:45
3011.67:086:43

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.27 kWh/m².

For context, solar energy here swings from a low near 1.38 kWh/m² to a high of 6.08 kWh/m² in June across the year — September's 4.27 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.9Bright
24.8Bright
34.8Bright
44.8Bright
54.7Bright
64.7Bright
74.7Bright
84.6Bright
94.6Bright
104.5Bright
114.5Bright
124.4Bright
134.3Bright
144.3Bright
154.3Bright
164.2Bright
174.2Bright
184.1Bright
194.1Bright
204.0Bright
214.0Moderate
223.9Moderate
233.9Moderate
243.8Moderate
253.8Moderate
263.7Moderate
273.7Moderate
283.6Moderate
293.6Moderate
303.5Moderate
Planning a trip in September

Is September a good time to visit Biarritz?

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

6.5
Sightseeing
3rd-best month of the year
4.6
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Biarritz for sightseeing.

What to pack for Biarritz in September

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

In September, Biarritz sees daytime highs around 22°C and nights near 16°C. Worth packing: light clothes and rain gear. About 11 days see rain.

light clothesrain gear

Sea temperature near Biarritz in September

The nearest coast averages about 21°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 17 km away) is warmest in August at about 22°C and coldest in February near 12°C.

It's comfortable for a long swim from Jul 1 to Sep 24 — about 2.8 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan13Bracing
Feb12Bracing
Mar12Bracing
Apr14Bracing
May16Cool
Jun19Cool
Jul21Refreshing
Aug22Refreshing
Sep21Refreshing
Oct18Cool
Nov16Cool
Dec14Bracing

UV index in Biarritz 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 Biarritz peaks around July 16 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 16UV 8Dec 22UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr6High
May6High
Jun8Very high
Jul8Very high
Aug8Very high
Sep5High
Oct4Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Biarritz?

Biarritz sits at 43.5°N, 1.6°W, 39 m above sea level, in France. The nearest listed city is Anglet, 3.0 km away.

Topography around Biarritz

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

Within 3 km, the terrain around Biarritz has only modest variations in elevation — a maximum elevation change of 91 m around an average of 28 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 231 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,044 m.

The land around Biarritz is covered by water (43%) and artificial surfaces (30%) within 3 km, water (47%) and trees (30%) within 16 km, and trees (46%) and water (25%) within 80 km.

3 km
91 m
16 km
231 m
80 km
2,044 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Anglet 3.0 km · Bayonne 7.0 km · Hondarribia 23 km · Irun 25 km · Errenteria 34 km · Pasaia 35 km · San Sebastian 39 km · Hernani 41 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 Biarritz (43.4806°, -1.5568°, elevation 39 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).