San Sebastián
September
Weather in San Sebastián for September 2025
Your guide to San Sebastián weather in September - trends and predictions
In general, the average temperature in San Sebastián at the beginning of September is 21.3 °C. As the month progressed, temperatures tended to slightly decrease, reaching an average of 21.1 °C by the end of September.
Expect significant rainfall in San Sebastián during September, with an average of 18 rainy days.
Is September a good time to visit San Sebastián? check out the best time to travel to San Sebastián page.
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12
Dry days
18
Rainy days
0
Snow days
23°/16°
Temperatures
12 km/h
Avg max wind
74 %
Avg humidity
San Sebastián in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  22° | 2  19° | 3  20° | 4  22° | 5  21° | 6 22° | 7 23° |
| 8 23° | 9  23° | 10 21° | 11 21° | 12  18° | 13 18° | 14 21° |
| 15  22° | 16  22° | 17 21° | 18 21° | 19 21° | 20 22° | 21 20° |
| 22 16° | 23 19° | 24 20° | 25 24° | 26 21° | 27 19° | 28 19° |
| 29 22° | 30 23° |
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Temperatures trend during September in San Sebastián
See the weather trend as well as the moving average line
September weather day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. | Cloudy | 22° /15° | 2.4 mm | 5 | |
| 2 Sept. | Moderate or heavy rain with thunder | 19° /15° | 14.4 mm | 5 | |
| 3 Sept. | Partly cloudy | 20° /15° | 2.9 mm | 5 | |
| 4 Sept. | Patchy rain possible | 22° /16° | 7.7 mm | 5 | |
| 5 Sept. | Sunny | 21° /15° | 8.2 mm | 6 | |
| 6 Sept. | Patchy rain possible | 22° /15° | 2.8 mm | 5 | |
| 7 Sept. | Partly cloudy | 23° /15° | 0.8 mm | 6 | |
| 8 Sept. | Partly cloudy | 23° /16° | 0.7 mm | 6 | |
| 9 Sept. | Patchy light rain with thunder | 23° /15° | 2.4 mm | 5 | |
| 10 Sept. | Patchy rain possible | 21° /15° | 2.2 mm | 5 | |
| 11 Sept. | Patchy light rain with thunder | 21° /15° | 2.4 mm | 5 | |
| 12 Sept. | Moderate or heavy rain shower | 18° /14° | 12.7 mm | 4 | |
| 13 Sept. | Partly cloudy | 18° /13° | 1 mm | 5 | |
| 14 Sept. | Partly cloudy | 21° /12° | 0 mm | 6 | |
| 15 Sept. | Thundery outbreaks possible | 22° /13° | 0 mm | 6 | |
| 16 Sept. | Patchy light drizzle | 22° /14° | 0.2 mm | 6 | |
| 17 Sept. | Partly cloudy | 21° /15° | 0.3 mm | 5 | |
| 18 Sept. | Patchy rain possible | 21° /14° | 0.8 mm | 6 | |
| 19 Sept. | Patchy rain possible | 21° /14° | 2 mm | 5 | |
| 20 Sept. | Sunny | 22° /14° | 3.2 mm | 6 | |
| 21 Sept. | Light rain shower | 20° /14° | 6.8 mm | 5 | |
| 22 Sept. | Light rain shower | 16° /13° | 5 mm | 4 | |
| 23 Sept. | Patchy rain possible | 19° /11° | 0.2 mm | 5 | |
| 24 Sept. | Sunny | 20° /13° | 0.9 mm | 5 | |
| 25 Sept. | Sunny | 24° /14° | 0.2 mm | 6 | |
| 26 Sept. | Patchy rain possible | 21° /15° | 12.3 mm | 5 | |
| 27 Sept. | Cloudy | 19° /13° | 3.1 mm | 5 | |
| 28 Sept. | Sunny | 19° /12° | 2.3 mm | 5 | |
| 29 Sept. | Patchy rain possible | 22° /14° | 0.1 mm | 6 | |
| 30 Sept. | Sunny | 23° /15° | 0 mm | 6 | |
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Important Notice
Our weather forecast for San Sebastián in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the San Sebastián forecast closer to your planned date for the most up-to-date weather information.
San Sebastián in September - FAQ
What are the expected maximum and minimum temperatures in San Sebastián during September?
During September, expect a variety of temperatures with highs around 23° and lows near 16°, suitable for diverse activities and preferences.
How much rainfall should be expected in San Sebastián during September?
Moderate rainfall is anticipated in San Sebastián during September, with a total of 90.2 mm spread over approximately 18 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in San Sebastián during September?
The average wind speed in San Sebastián during September is 12 km/h, suggesting breezy to windy conditions, depending on your activities.
What to pack to San Sebastián in September?
As you prepare for your trip to San Sebastián in September, it's important to consider the typical weather patterns for the time of year. Below is a carefully tailored packing list to ensure that your time in San Sebastián, during September, is comfortable and enjoyable, regardless of the weather conditions.
- Clothing
- Layered Clothing: Light sweaters, long-sleeve shirts, light jackets, and comfortable pants
- Rain Gear: Lightweight, waterproof clothing
- Footwear
- Waterproof Shoes
- Accessories
- Sunglasses: For sun protection
- Sun Hats: Wide-brimmed hats for sun protection in warm weather
- Umbrellas/Raincoats: For rainy days
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