The highest day temperature in September 2026 was 78°F. The lowest night temperature was 59°F. The average values for day and night temperatures during September were 71.0°F и 65.4°F respectivly.

The average sea surface temperature in September 2026 for La Rochelle was 72.5°F. The maximum and minimum values were 68.8°F and 75.0°F respectively.

Most of the days in September are sunny but you can also expect cloudy and gloomy days.

Precipitation total in September for La Rochelle is 1.3 in. It makes september one of the least rainy months of the year.

The average wind speed in September is 10.7 mph. It makes September one of the most windless months of the year for La Rochelle.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for La Rochelle in September is 8.5 hours.