Fos-sur-Mer in Summer
In summer (June, July and August), Fos-sur-Mer sees average daytime highs around 30°C and overnight lows near 19°C, with 64 mm of rain over about 11 wet days across the season. It is the warmest season of the year and the driest season of the year.
Over the season highs climb from about 26°C in early June to 29°C by late August. The sky is clear or mostly clear about 67% of the time across summer, and the air most often feels dry.
Summer is Fos-sur-Mer's 3rd-best season to visit on our travel score. For the whole year in context, see Fos-sur-Mer's year-round climate.
- Avg daytime high
- 30°C
- warmest season of the year
- Avg overnight low
- 19°C
- Rainfall
- 64 mm
- 11 wet days
- Avg wind
- 14 km/h
- Travel score
- 6.3
- 3rd-best season
- Months
- Jun · Jul · Aug
Temperature in Fos-sur-Mer in Summer
Over the season highs climb from about 26°C in early June to 29°C by late August.
A typical summer day in Fos-sur-Mer reaches about 30°C and drops to 19°C overnight. The warmest of the three months is July, the coolest June.
Fos-sur-Mer weather by month
How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 12° / 4° | 52 | 6.5 | 9.1 | 3.4 |
| Feb | 13° / 4° | 38 | 5.4 | 10.2 | 4.1 |
| Mar | 16° / 7° | 37 | 5.7 | 11.6 | 6.0 |
| Apr | 19° / 10° | 60 | 8 | 13.2 | 6.7 |
| May | 23° / 14° | 50 | 6.5 | 14.5 | 7.5 |
| Jun | 28° / 18° | 27 | 4.3 | 15.2 | 7.1 |
| Jul | 31° / 20° | 15 | 2.8 | 14.9 | 5.9 |
| Aug | 30° / 20° | 23 | 3.6 | 13.8 | 5.9 |
| Sep | 26° / 16° | 74 | 6.3 | 12.3 | 7.5 |
| Oct | 21° / 13° | 82 | 8.4 | 10.8 | 6.8 |
| Nov | 16° / 8° | 85 | 9.4 | 9.5 | 5.0 |
| Dec | 12° / 5° | 50 | 7 | 8.8 | 3.6 |
Cloud cover in Summer
The sky is clear or mostly clear about 67% of the time across summer.
Chance of precipitation in Summer
Fos-sur-Mer gets around 64 mm of rain over 11 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 14 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 15 hours in early June to 13 h 06 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 7.0 kWh/m².
Is summer a good time to visit Fos-sur-Mer?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit Fos-sur-Mer for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Fos-sur-Mer in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Fos-sur-Mer sees daytime highs around 30°C and nights near 19°C. Pack light clothes and sun protection. About 11 days see rain.
Sea temperature near Fos-sur-Mer in Summer
The nearest coast averages about 21°C across summer — 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 13 | 12 | 13 | 14 | 16 | 19 | 21 | 22 | 21 | 19 | 17 | 14 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Cool | Cool | Refreshing | Refreshing | Refreshing | Cool | Cool | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 13 | Bracing |
| Feb | 12 | Bracing |
| Mar | 13 | Bracing |
| Apr | 14 | Bracing |
| May | 16 | Cool |
| Jun | 19 | Cool |
| Jul | 21 | Refreshing |
| Aug | 22 | Refreshing |
| Sep | 21 | Refreshing |
| Oct | 19 | Cool |
| Nov | 17 | Cool |
| Dec | 14 | Bracing |
UV index in Fos-sur-Mer in Summer
Clear-sky midday UV across summer averages around 8 — enough to warrant sun protection. 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 2 | 4 | 6 | 6 | 7 | 9 | 7 | 5 | 3 | 2 | 1 |
| Level | Low | Moderate | Moderate | High | High | Very high | Very high | High | High | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 2 | Moderate |
| Mar | 4 | Moderate |
| Apr | 6 | High |
| May | 6 | High |
| Jun | 7 | Very high |
| Jul | 9 | Very high |
| Aug | 7 | High |
| Sep | 5 | High |
| Oct | 3 | Moderate |
| Nov | 2 | Low |
| Dec | 1 | Low |
Air quality in Fos-sur-Mer in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer 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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 13 | 15 | 17 | 17 | 15 | 16 | 14 | 15 | 13 | 13 | 11 | 12 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 13 | Moderate |
| Feb | 15 | Moderate |
| Mar | 17 | Moderate |
| Apr | 17 | Moderate |
| May | 15 | Moderate |
| Jun | 16 | Moderate |
| Jul | 14 | Moderate |
| Aug | 15 | Moderate |
| Sep | 13 | Moderate |
| Oct | 13 | Moderate |
| Nov | 11 | Good |
| Dec | 12 | Moderate |
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.
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
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.