Weather in Donostia / San Sebastián for September 2026
In general, the average temperature in Donostia / San Sebastián at the beginning of September is 24.3 °C. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 21.4 °C by the end of September.
Donostia / San Sebastián experiences heavy rainfall in September, with over 20 rainy days and an average total precipitation 171 mm.
Is September a good time to visit Donostia / San Sebastián? check out the best time to travel to Donostia / San Sebastián page.
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Donostia / San Sebastián Weather September
Temperatures trend during September in Donostia / San Sebastián
September weather in Donostia / San Sebastián day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. |  Patchy light rain with thunder | 22° /15° | 7 mm | 5 | |
| 2 Sept. |  Moderate or heavy rain shower | 23° /16° | 20.3 mm | 5 | |
| 3 Sept. |  Cloudy | 25° /16° | 3.2 mm | 5 | |
| 4 Sept. |  Light rain shower | 24° /17° | 3.9 mm | 6 | |
| 5 Sept. |  Partly cloudy | 24° /15° | 2.5 mm | 6 | |
| 6 Sept. |  Sunny | 26° /16° | 12.2 mm | 7 | |
| 7 Sept. | Partly cloudy | 26° /17° | 1.2 mm | 7 | |
| 8 Sept. | Patchy rain possible | 23° /15° | 4.9 mm | 5 | |
| 9 Sept. | Light rain shower | 23° /15° | 2.9 mm | 5 | |
| 10 Sept. | Patchy rain possible | 22° /15° | 3.2 mm | 5 | |
| 11 Sept. | Moderate or heavy rain shower | 23° /15° | 19.6 mm | 5 | |
| 12 Sept. | Cloudy | 20° /15° | 11.6 mm | 4 | |
| 13 Sept. | Light rain shower | 19° /14° | 1.7 mm | 4 | |
| 14 Sept. | Cloudy | 22° /13° | 0 mm | 5 | |
| 15 Sept. | Sunny | 22° /14° | 0.8 mm | 6 | |
| 16 Sept. | Partly cloudy | 23° /14° | 0.2 mm | 6 | |
| 17 Sept. |  Patchy light drizzle | 24° /14° | 0.6 mm | 6 | |
| 18 Sept. | Light rain shower | 25° /14° | 0.4 mm | 7 | |
| 19 Sept. | Patchy rain possible | 26° /16° | 0.3 mm | 6 | |
| 20 Sept. | Sunny | 25° /15° | 4.6 mm | 6 | |
| 21 Sept. | Light rain shower | 21° /14° | 12.7 mm | 5 | |
| 22 Sept. | Light rain shower | 18° /12° | 11.3 mm | 4 | |
| 23 Sept. | Light rain shower | 18° /11° | 3 mm | 4 | |
| 24 Sept. | Sunny | 22° /12° | 2.3 mm | 5 | |
| 25 Sept. | Sunny | 22° /12° | 0.8 mm | 6 | |
| 26 Sept. | Patchy rain possible | 21° /13° | 3.8 mm | 5 | |
| 27 Sept. |  Overcast | 21° /12° | 4.4 mm | 5 | |
| 28 Sept. | Sunny | 21° /13° | 4.9 mm | 6 | |
| 29 Sept. | Partly cloudy | 21° /13° | 0 mm | 5 | |
| 30 Sept. | Partly cloudy | 22° /13° | 0 mm | 6 | |
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Donostia / San Sebastián weather in September vs August vs October
| August | September | October | |
|---|---|---|---|
| Weather | Patchy rain possible | Patchy rain possible | Patchy rain possible |
| Temperatures | 23°/16° | 22°/15° | 20°/13° |
| Rainfall | 136 mm | 171 mm | 131 mm |
| Wind | 13.7 km/h | 14.5 km/h | 17.7 km/h |
| Humidity | 79% | 76% | 74% |
| Rainy days | 19 days | 21 days | 20 days |
| Dry days | 12 days | 9 days | 11 days |
Planning a trip to Donostia / San Sebastián? Discover the best time to visit
Donostia / San Sebastián in September - FAQ
What to pack to Donostia / San Sebastián in September?
As you prepare for your trip to Donostia / 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 Donostia / 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 Donostia / San Sebastián
UV exposure in Donostia / San Sebastián during September
Quick links
Where is Donostia / San Sebastián?Get accurate weather forecasts for Donostia / San Sebastián, located at latitude 43.313 and longitude -1.975. Stay updated with localized weather information tailored for Donostia / San Sebastián.