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 21.4 °C. As the month progressed, temperatures tended to moderately rise, reaching an average of 22.1 °C by the end of September.
The climate of San Sebastián in September is notably wet, with an average of 15 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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15
Dry days
15
Rainy days
0
Snow days
23°/15°
Temperatures
11 km/h
Avg max wind
78 %
Avg humidity
San Sebastián in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  22° | 2 17° | 3  21° | 4  23° | 5  22° | 6  22° | 7 23° |
| 8 24° | 9 23° | 10 21° | 11 21° | 12 18° | 13  20° | 14 21° |
| 15 23° | 16 22° | 17 23° | 18 21° | 19 21° | 20  23° | 21 19° |
| 22 19° | 23 20° | 24 22° | 25 24° | 26 21° | 27 20° | 28 21° |
| 29 23° | 30 24° |
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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. | Light rain shower | 22° /15° | 10.1 mm | 5 | |
| 2 Sept. | Light rain shower | 17° /14° | 16.8 mm | 4 | |
| 3 Sept. | Mist | 21° /14° | 2.1 mm | 5 | |
| 4 Sept. | Patchy light rain | 23° /15° | 3.6 mm | 6 | |
| 5 Sept. | Partly cloudy | 22° /14° | 5.1 mm | 6 | |
| 6 Sept. | Sunny | 22° /13° | 1.6 mm | 6 | |
| 7 Sept. | Patchy rain possible | 23° /14° | 1.8 mm | 6 | |
| 8 Sept. | Patchy rain possible | 24° /14° | 1.6 mm | 6 | |
| 9 Sept. | Light rain shower | 23° /15° | 4.3 mm | 6 | |
| 10 Sept. | Light rain shower | 21° /13° | 1.5 mm | 5 | |
| 11 Sept. | Light rain shower | 21° /14° | 7.7 mm | 5 | |
| 12 Sept. | Mist | 18° /14° | 3.9 mm | 4 | |
| 13 Sept. | Cloudy | 20° /13° | 0.2 mm | 5 | |
| 14 Sept. | Cloudy | 21° /13° | 0 mm | 5 | |
| 15 Sept. | Partly cloudy | 23° /13° | 0 mm | 7 | |
| 16 Sept. | Patchy light drizzle | 22° /13° | 0.6 mm | 6 | |
| 17 Sept. | Patchy rain possible | 23° /13° | 1.3 mm | 6 | |
| 18 Sept. | Light rain shower | 21° /13° | 0.9 mm | 5 | |
| 19 Sept. | Partly cloudy | 21° /14° | 0 mm | 6 | |
| 20 Sept. | Overcast | 23° /13° | 2.1 mm | 5 | |
| 21 Sept. | Light rain shower | 19° /14° | 6.5 mm | 4 | |
| 22 Sept. | Light rain shower | 19° /12° | 3.5 mm | 4 | |
| 23 Sept. | Sunny | 20° /11° | 0.1 mm | 6 | |
| 24 Sept. | Sunny | 22° /12° | 1.2 mm | 6 | |
| 25 Sept. | Sunny | 24° /13° | 1.7 mm | 6 | |
| 26 Sept. | Patchy rain possible | 21° /14° | 13 mm | 5 | |
| 27 Sept. | Sunny | 20° /13° | 3 mm | 5 | |
| 28 Sept. | Sunny | 21° /13° | 1 mm | 6 | |
| 29 Sept. | Patchy rain possible | 23° /14° | 0 mm | 5 | |
| 30 Sept. | Sunny | 24° /15° | 0.5 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 15°, suitable for diverse activities and preferences.
How much rainfall should be expected in San Sebastián during September?
Significant rainfall exceeding 108.5 mm is expected in San Sebastián during September, occurring over more than 15 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in San Sebastián during September?
The average wind speed in San Sebastián during September is 11 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
September rainfall patterns in San Sebastián
Explore the daily rainfall trends and prepare for San Sebastiáns September weather 💧
UV exposure in San Sebastián during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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