San Sebastian weather in September 2025

Expect 23°C daytime maximum temperatures in the shade with on average 6 hours of sunshine per day in San Sebastian in September. Check more long-term weather averages for San Sebastian in September before you book your next holiday to Spain in 2025/2026.

  • 23°C maximum daytime temperature in September in San Sebastian23
    23°C max day temperature
  • 6 hours of sunshine per day
  • 13 days with some rainfall in September in San Sebastian13
    13 days with some rainfall
  • 14°C minimum night-time temperature in September in San Sebastian14
    14°C min night temperature
  • 12 hours of daylight per day in September in San Sebastian12
    12 hours of daylight per day
  • No heat & humidity in September in San Sebastian0
    No heat & humidity
  • 97 mm monthly rainfall in September in San Sebastian97
    97 mm of monthly rainfall
  • UV (maximum) index 5 (Moderate) in September in San Sebastian5
    5 (Moderate) UV index
  • 21°C sea temperature in September in San Sebastian21
    21°C sea temperature

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The September weather guide for Spain (San Sebastian) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

Metric (°C / mm)  |  Imperial (°F / inches)

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How hot is it in San Sebastian in September?

Daytime temperatures usually reach 23°C in San Sebastian in September, falling to 14°C at night.

How sunny is it in San Sebastian in September?

There are normally 6 hours of bright sunshine each day in San Sebastian in September - that's 47% of daylight hours.

How warm is the sea around San Sebastian in September?

The average sea temperature around San Sebastian in September is 21°C.

Does it rain in San Sebastian in September?

There are usually 13 days with some rain in San Sebastian in September and the average monthly rainfall is 97mm.

San Sebastian September sunrise & sunset times

Browse the sunrise and sunset times for San Sebastian in September 2025. Select a month to view San Sebastian sunrise and sunset times for the next 12 months.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Monday, 1st September 2025 06:32 19:43
Monday, 15th September 2025 06:48 19:18
Tuesday, 30th September 2025 07:04 18:51

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