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September Weather in Saint-Sebastien, France

Last updated: August 23, 2025

In September, the average temperature in Saint-Sebastien, France hovers around 17°C (64°F). Visitors can expect a range of temperatures, with a minimum of 4°C (39°F) and a maximum of 35°C (95°F). This month also sees 52 mm (2.0 in) of precipitation spread over 8 days, contributing to an average humidity of 76%.

September Temperature in Saint-Sebastien

In September in Saint-Sebastien, the average temperature is 17°C (64°F). The maximum can reach 35°C (95°F) and the minimum can be as low as 4°C (39°F). This makes it an ideal destination for travelers seeking a pleasant climate with comfortable daytime temperatures and cooler evenings.

September Weather in Saint-Sebastien: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Saint-Sebastien, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Saint-Sebastien, September typically has an average temperature of 17°C (64°F), with highs reaching up to 35°C (95°F) and lows dropping to around 4°C (39°F).
JanFebMarAprMayJunJulAugSepOctNovDec404548535967706963564744
Data source: Temperature data for Saint-Sebastien generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Saint-Sebastien

In Saint-Sebastien in September, the total precipitation amount is 52 mm (2.0 in) recorded over a span of 8 days.

September Precipitation Trends in Saint-Sebastien

The chart displays monthly precipitation patterns in Saint-Sebastien, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Saint-Sebastien, September typically receives around 52 mm (2.0 inches) of precipitation spread over approximately 8 days.
JanFebMarAprMayJunJulAugSepOctNovDec7170785986764436527270118
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Saint-Sebastien

In Saint-Sebastien in September, humidity is 76%. With an average temperature of 17°C (64°F), this humidity feels like a warm, sticky embrace that can make outdoor activities feel sluggish and draining, challenging travelers to stay hydrated and seek respite in shaded areas or air-conditioned spaces.

September Average Humidity in Saint-Sebastien

This chart illustrates the average monthly humidity levels in Saint-Sebastien, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Saint-Sebastien is approximately 76%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec90%88%85%84%83%79%71%68%76%87%91%93%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Saint-Sebastien

In Saint-Sebastien in September, the maximum UV index is 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in Saint-Sebastien, you can refer to this Hourly UV Index in Saint-Sebastien.

Maximum UV Index Levels in Saint-Sebastien for September

The chart shows the monthly maximum UV Index (UVI) for Saint-Sebastien in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Saint-Sebastien typically reaches 6, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec2357891096532
Data source: Saint-Sebastien September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How September Weather in Saint-Sebastien Compares to Other Months

Weather in Saint-Sebastien varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Saint-Sebastien, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Saint-Sebastien, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather5°C (41°F)71 mm (2.8 inches)90%low
February Weather7°C (45°F)70 mm (2.8 inches)88%moderate
March Weather9°C (48°F)78 mm (3.1 inches)85%moderate
April Weather12°C (53°F)59 mm (2.3 inches)83%high
May Weather15°C (59°F)86 mm (3.4 inches)83%very high
June Weather19°C (67°F)76 mm (3.0 inches)79%very high
July Weather21°C (71°F)44 mm (1.7 inches)71%very high
August Weather21°C (70°F)36 mm (1.4 inches)68%very high
September Weather17°C (64°F)52 mm (2.0 inches)76%high
October Weather13°C (56°F)72 mm (2.8 inches)87%moderate
November Weather8°C (47°F)70 mm (2.7 inches)91%moderate
December Weather7°C (44°F)118 mm (4.6 inches)93%low

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