Dax weather in September

In September, Dax sees average daytime highs of 25°C and overnight lows near 14°C, with 66 mm of rain across 9.2 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 26°C in the first days to 23°C by the end. The sky is clear or mostly clear about 37% of the time in September, and the air most often feels comfortable.

Daylight stretches from about 13 h 06 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Dax's 3rd-clearest and 11th-windiest month. For the whole year in context, see Dax's year-round climate.

Daytime high
25°
4th warmest
Overnight low
14°
9th coldest
Rainfall
66 mm
9.2 wet days
Daylight
12 h 18 min
6:50 AM – 7:07 PM
Cloud cover
52%
3rd clearest
Wind
8 km/h
11th windiest
Solar energy
4.29 kWh/m²
Travel score
7.0
out of 10
Air quality
Good
PM2.5 8.7 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 26°C in the first days to 23°C by the end.

A typical September day in Dax reaches about 25°C in the afternoon and slips back to 14°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 30°C. Set against its neighbours, September runs about 3°C cooler than August and about 4°C warmer than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12615
22615
32615
42615
52615
62615
72615
82615
92515
102515
112514
122514
132514
142514
152514
162514
172414
182414
192414
202414
212414
222413
232413
242313
252313
262313
272313
282313
292313
302313

Dax weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan11° / 8712.49.12.7
Feb13° / 7410.710.23.3
Mar16° / 751211.64.8
Apr18° / 9013.413.25.4
May21° / 12°8112.714.56.1
Jun25° / 15°669.215.26.9
Jul27° / 17°518.614.96.9
Aug27° / 17°578.513.86.9
Sep25° / 14°669.212.37.0
Oct20° / 11°8311.310.86.1
Nov15° / 10513.69.54.1
Dec12° / 9112.88.82.9

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 37% 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 45%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16139
26040
36139
46139
56139
66040
76040
85941
95941
105842
115743
125743
135644
145545
155545
165545
175347
185347
195347
205248
215248
225248
235248
245149
255050
265050
274951
284951
294951
304852

Chance of precipitation in September

Any precipitation

Dax gets around 66 mm of rain over 9.2 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 32% and peaks near 35% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
129
229
328
428
529
629
729
829
930
1030
1131
1232
1332
1432
1533
1633
1733
1833
1933
2033
2133
2233
2333
2433
2534
2634
2734
2834
2935
3035

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 36% of days. Sticky, muggy-or-worse air turns up on roughly 5% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
122303314
223303313
324313312
426313211
527313111
628323110
72832319
82932308
93033308
103133297
113134296
123234286
133235285
143335275
153436264
163536264
173537253
183637243
193737232
203838222
213939212
223939201
234040201
244040191
254040181
264140181
274240171
284340171
294440161
304539151

Wind in September

Winds average 8 km/h in September.

Across September, daily wind ranges from about 8 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 06 min 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 90 minutes over September. Sunrise moves from 6:32 AM to 7:06 AM, and sunset from 7:36 PM to 6:41 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.16:327:36
213.06:337:34
313.06:357:32
412.96:367:30
512.96:377:28
612.86:387:26
712.86:397:24
812.76:407:23
912.76:427:21
1012.66:437:19
1112.66:447:17
1212.56:457:15
1312.46:467:13
1412.46:477:11
1512.36:497:09
1612.36:507:07
1712.26:517:05
1812.26:527:04
1912.16:537:02
2012.16:547:00
2112.06:566:58
2212.06:576:56
2311.96:586:54
2411.96:596:52
2511.87:006:50
2611.87:016:48
2711.77:036:46
2811.77:046:45
2911.67:056:43
3011.67:066:41

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.29 kWh/m².

For context, solar energy here swings from a low near 1.36 kWh/m² to a high of 6.13 kWh/m² in June across the year — September's 4.29 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.9Bright
24.9Bright
34.8Bright
44.8Bright
54.8Bright
64.7Bright
74.7Bright
84.6Bright
94.6Bright
104.5Bright
114.5Bright
124.4Bright
134.4Bright
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 Dax?

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

7.0
Sightseeing
1st-best month of the year
6.1
Beach & pool
4th-best month of the year

September is one of the better times to visit Dax for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Dax in September

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

In September, Dax sees daytime highs around 25°C and nights near 14°C. Worth packing: light clothes and rain gear. About 9 days see rain.

light clothesrain gear

Sea temperature near Dax 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 32 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 3 to Sep 23 — about 2.7 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 Dax 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 Dax peaks around July 17 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 17UV 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 Dax?

Dax sits at 43.7°N, 1.1°W, 16 m above sea level, in France. The nearest listed city is Bayonne, 42 km away.

Topography around Dax

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

Within 3 km, the terrain around Dax has only modest variations in elevation — a maximum elevation change of 48 m around an average of 17 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 168 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,044 m.

The land around Dax is covered by trees (37%), artificial surfaces (33%) and grassland (20%) within 3 km, trees (52%), cropland (24%) and grassland (21%) within 16 km, and trees (45%) and grassland (20%) within 80 km.

3 km
48 m
16 km
168 m
80 km
2,044 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Bayonne 42 km · Anglet 45 km · Biarritz 48 km · Mont-de-Marsan 49 km · Hondarribia 71 km · Pau 72 km · Irun 72 km · Errenteria 82 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 Dax (43.7103°, -1.0537°, elevation 16 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).