September 12 is generally a great time to visit San Sebastian. While there is a slight chance of rain (31%), showers are usually brief. Expect comfortable 23°C weather. San Sebastian is currently in its most popular travel window, meaning vibrant crowds and premium pricing.
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Essential Travel Info for San Sebastian
Currency
EUR
€ Euro
Language
Spanish
+3 more
Driving
Right side
Safety
High Safety
GPI: 1.603
San Sebastian Weather Forecast for September 12
"Mild & Comfortable. Expect average highs of 22.5°C. 31% chance of rain."
What to Wear in San Sebastian in September
Based on historical data for September 12, San Sebastian typically experiences temperatures between 16.4°C and 22.5°C. We recommend packing t-shirt, light clothing, umbrella to stay comfortable. With a 31% chance of rain, keeping a raincoat or umbrella handy is a smart move.
Complete Packing Guide
Weekly breakdown & essential items for San Sebastian
Smart Suitcase
- T-Shirt
- Light Clothing
- Umbrella
Average High
22.5°C
Daytime Peak
Average Low
16.4°C
Nighttime Low
Feels Like
23°C
☀️ Feels accurate
Rain Chance
31%
Avg 2.7mm if it rains
Cloud Cover
60%
Overcast
Pressure
1018.2 hPa
Medium volatility
San Sebastian Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
~ Weather is generally predictable, but pack for minor variations. A light backup layer is recommended.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 15 for extended outdoor time
Type I-II
🔴 32 min to burn
Type III-IV
🟡 48 min to burn
Type V-VI
🟢 80 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
18.9°C
Noticeable
Heat Stress
Low
No heat warning
🙂 Best outdoor time:
Any time during daylight hours
Marine Conditions
Marine Life
No special warnings. Enjoy the swim!
Swim Index
⚠️ Mixed Conditions
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in Spain
Flight Traffic
High
97/100 pressure index
Health Advisory
Required
1 vaccine • View Details →
Landing Slots
~29
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in San Sebastian
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
06:45
☀️ Noon
13:05
🌇 Sunset
19:26
⏱️ Daylight
12h 41m
Wind Speed
14 km/h
Gentle breeze
Sunshine
9.1 hrs
Direct Sun (Cloud-free)
Humidity
80%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for San Sebastian
Smart Flight Estimator
Airport-to-Airport Logistics
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Travel Health & Safety in San Sebastian
Travel Comfort Index
Real-time tourism conditions
Weather Quality
⛅ Good
Tourist Crowds
🟡 Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Moderate fluctuations. Some sensitivity possible.
Weather unlikely to affect joint pain.
Moderate fish activity expected.
Air quality is excellent. Perfect for outdoor activities.
Regional Safety Profile
Seismic Activity
Rare minor tremors. Buildings are earthquake-resistant.
"According to 30YearWeather's analysis of 30 years of NASA satellite data, San Sebastian on September 12 averages 22.5°C with a 31% precipitation probability. Wedding/Outdoor Event Score: 94/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
San Sebastian Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Better Alternatives Nearby
Consider these dates within ±7 days
September 5
23.6°C • 30% rain
Score
96
September 13
22.5°C • 29% rain
Score
96
September 16
22.1°C • 29% rain
Score
96
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (September 12) in other destinations
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📍 Is San Sebastian Worth Visiting on September 12?
Planning a trip to San Sebastian on September 12? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year is characterized by pleasant mild weather averaging 22.5°C with a 31% historical precipitation risk.
✈️ Travel Logistics: Approximately 29 landing slots available daily during this period, indicating manageable crowd levels.
💉 Health Advisory: 7 vaccinations are recommended for Spain, including COVID-19.
🌊 Coastal Conditions: Water temperature averages 22.2°C (swimming pool). Wave conditions are generally surfers only with heights around 1.3m.
📊 Historical Extremes: The hottest September 12 recorded in the last 30 years saw temperatures hit 35.6°C in 2022, while the coldest dropped to 13.2°C in 2024.