Fos-sur-Mer weather in December

In December, Fos-sur-Mer sees average daytime highs of 12°C and overnight lows near 5°C, with 50 mm of precipitation across 7 wet days and about 8.8 hours of daylight. It is the 11th-warmest and 6th-wettest month of the year here.

Day-to-day highs hold fairly steady near 12°C through the month. The sky is clear or mostly clear about 44% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 hours at the start of December to 8 h 48 min by month's end. Set against the rest of the year, December is Fos-sur-Mer's 10th-clearest and 5th-windiest month. For the whole year in context, see Fos-sur-Mer's year-round climate.

Daytime high
12°
11th warmest
Overnight low
3rd coldest
Precipitation
50 mm
7 wet days
Daylight
8 h 48 min
8:13 AM – 5:00 PM
Cloud cover
49%
10th clearest
Wind
16 km/h
5th windiest
Solar energy
1.6 kWh/m²
Travel score
3.6
out of 10
Air quality
Good
PM10 19.9 µg/m³ · 2019

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

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 12°C through the month.

A typical December day in Fos-sur-Mer reaches about 12°C in the afternoon and slips back to 5°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 8°C and 16°C. Set against its neighbours, December runs about 3°C cooler than November and on par with January.

-5°10°15°20°151015202531
Avg high (°C)Avg low (°C)
1136
2136
3136
4136
5136
6136
7136
8135
9135
10135
11125
12125
13125
14125
15125
16125
17125
18125
19125
20125
21125
22125
23125
24125
25125
26125
27125
28125
29125
30124
31124

Fos-sur-Mer weather by month

How December compares with the rest of the year at a glance. December is the 11th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan12° / 526.59.13.4
Feb13° / 385.410.24.1
Mar16° / 375.711.66.0
Apr19° / 10°60813.26.7
May23° / 14°506.514.57.5
Jun28° / 18°274.315.27.1
Jul31° / 20°152.814.95.9
Aug30° / 20°233.613.85.9
Sep26° / 16°746.312.37.5
Oct21° / 13°828.410.86.8
Nov16° / 859.49.55.0
Dec12° / 5078.83.6

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 44% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 14% of December, with mostly cloudy or overcast conditions the remaining 42%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15842
25842
35941
45941
55941
65941
75941
85941
95941
105941
115941
126040
136040
146040
155941
165941
175842
185842
195743
205743
215644
225644
235644
245644
255644
265545
275545
285545
295644
305644
315644

Chance of precipitation in December

Any precipitation

Fos-sur-Mer gets around 50 mm of rain and snow over 7 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 23% and peaks near 26% on the wettest days, and about 0 day brings snow.

0%10%20%30%40%151015202531
Rain chance (%)
126
225
325
424
524
624
723
823
923
1023
1122
1222
1322
1422
1522
1622
1722
1822
1922
2022
2122
2222
2322
2422
2522
2622
2722
2822
2921
3021
3121

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
1982
2982
3982
4991
5991
6991
7991
8991
91000
101000
111000
121000
131000
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
301000
311000

Wind in December

Winds average 16 km/h in December.

Across December, daily wind ranges from about 15 km/h on the calmest days to 16 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
116light breeze
216light breeze
316light breeze
416light breeze
516light breeze
616light breeze
716light breeze
816light breeze
916light breeze
1016light breeze
1116light breeze
1216light breeze
1316light breeze
1416light breeze
1516light breeze
1616light breeze
1716light breeze
1816light breeze
1916light breeze
2016light breeze
2116light breeze
2216light breeze
2316light breeze
2416light breeze
2516light breeze
2616light breeze
2716light breeze
2816light breeze
2916light breeze
3016light breeze
3115light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 hours at the start of December to 8 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 8:00 AM to 8:19 AM, and sunset from 5:00 PM to 5:08 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.08:005:00
29.08:015:00
39.08:025:00
48.98:035:00
58.98:044:59
68.98:054:59
78.98:064:59
88.98:064:59
98.98:074:59
108.88:084:59
118.88:094:59
128.88:104:59
138.88:114:59
148.88:115:00
158.88:125:00
168.88:135:00
178.88:135:00
188.88:145:01
198.88:155:01
208.88:155:01
218.88:165:02
228.88:165:02
238.88:175:03
248.88:175:03
258.88:175:04
268.88:185:04
278.88:185:05
288.88:185:06
298.88:195:06
308.88:195:07
318.88:195:08

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.6 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.6 kWh/m² to a high of 7.31 kWh/m² in July across the year — December's 1.6 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.7Dim
21.7Dim
31.7Dim
41.7Dim
51.7Dim
61.7Dim
71.7Dim
81.7Dim
91.6Dim
101.6Dim
111.6Dim
121.6Dim
131.6Dim
141.6Dim
151.6Dim
161.6Dim
171.6Dim
181.6Dim
191.6Dim
201.6Dim
211.6Dim
221.6Dim
231.6Dim
241.6Dim
251.6Dim
261.6Dim
271.6Dim
281.6Dim
291.6Dim
301.6Dim
311.6Dim
Planning a trip in December

Is December a good time to visit Fos-sur-Mer?

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

3.6
Sightseeing
11th-best month of the year
0.0
Beach & pool
11th-best month of the year

December is a weaker month for outdoor sightseeing in Fos-sur-Mer.

What to pack for Fos-sur-Mer in December

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

In December, Fos-sur-Mer sees daytime highs around 12°C and nights near 5°C. Worth packing: a warm layer. About 7 days see rain.

a warm layer

Sea temperature near Fos-sur-Mer in December

The nearest coast averages about 14°C in December — 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 22°C and coldest in February near 12°C.

It's comfortable for a long swim from Jun 28 to Sep 24 — about 2.9 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan13Bracing
Feb12Bracing
Mar13Bracing
Apr14Bracing
May16Cool
Jun19Cool
Jul21Refreshing
Aug22Refreshing
Sep21Refreshing
Oct19Cool
Nov17Cool
Dec14Bracing

UV index in Fos-sur-Mer in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 1. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Fos-sur-Mer peaks around July 15 at about 9 (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 15UV 9Dec 22UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar4Moderate
Apr6High
May6High
Jun7Very high
Jul9Very high
Aug7High
Sep5High
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Fos-sur-Mer in December

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Fos-sur-Mer is worst in March — around 17 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

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

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodMar 2417 µg/m³Nov 1911 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb15Moderate
Mar17Moderate
Apr17Moderate
May15Moderate
Jun16Moderate
Jul14Moderate
Aug15Moderate
Sep13Moderate
Oct13Moderate
Nov11Good
Dec12Moderate
Location & terrain

Where is Fos-sur-Mer?

Fos-sur-Mer sits at 43.4°N, 4.9°E, 6 m above sea level, in France. The nearest listed city is Port-de-Bouc, 5.0 km away.

Topography around Fos-sur-Mer

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Fos-sur-Mer.

Within 3 km, the terrain around Fos-sur-Mer has only modest variations in elevation — a maximum elevation change of 78 m around an average of 4 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 212 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,261 m.

The land around Fos-sur-Mer is covered by water (44%) and artificial surfaces (25%) within 3 km, water (43%) within 16 km, and trees (35%) and water (35%) within 80 km.

3 km
78 m
16 km
212 m
80 km
1,261 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwaterwetland
December weather nearby: Port-de-Bouc 5.0 km · Istres 9.0 km · Martigues 10 km · Miramas 17 km · Marignane 22 km · Vitrolles 25 km · Salon-de-Provence 26 km · Les Pennes-Mirabeau 30 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 Fos-sur-Mer (43.4377°, 4.9446°, elevation 6 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. 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).