Saint-Nazaire weather in September
Temperature, sea and sunshine in September: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in September
Poor
Best time to visit: July – August
What is the weather like in Saint-Nazaire in September?
In September, Saint-Nazaire is mild: daytime highs average 21 °C, and nights cool down to about 14 °C. The sea averages 17.6 °C – bracing, so a wetsuit helps for longer swims. The sun shines for around 7 hours a day. Rain falls on about 8 days, adding up to 44 mm. All in all, September is not an ideal month for a holiday in Saint-Nazaire.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 57 | 39 | 13 |
| Day | 23° | 21° | 17° |
| Night | 16° | 14° | 12° |
| Sea | 19° | 18° | 16° |
| Sun | 8 h | 7 h | 4 h |
| Rain days | 8 | 8 | 12 |
More details for September
- Daylight
- 12 h 39 min07:45 – 20:24
- UV index
- 5 · moderateclear sky, noon (estimate)All months
- Muggy days
- 1 daydew point 18 °C or moreAll months
- Wind
- 20 km/haverage daily peakAll months
- Cloud cover
- 52 %on averageAll months
- Hot days
- 0 days30 °C or moreAll months
- Time zone
- UTC+2Europe/Paris
How the score comes together
- Temperatureweight 35 %27 %
- Seaweight 25 %9 %
- Sunshineweight 20 %63 %
- Few rainy daysweight 20 %73 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Sun, sea & sand”.
What to pack in September
- Wetsuit for longer swims
- Sunscreen
- A jumper for the evenings
Saint-Nazaire in September: quick answers
Is Saint-Nazaire hot in September?
No. In September, Saint-Nazaire is mild: daytime highs average 21 °C and nights drop to about 14 °C.
Can you swim in Saint-Nazaire in September?
Only if you don't mind cold water: in September the sea averages just 17.6 °C. Comfortable swimming temperatures are not reached at any time of year.
Does it rain much in Saint-Nazaire in September?
Rain falls on about 8 days, adding up to 44 mm.
Saint-Nazaire month by month
The whole year in Saint-NazaireAll destinations: FranceWhere to go in SeptemberSea temperature in September
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences