30YearWeather
San Sebastian, September 25
San Sebastian street view during September
Historical Weather Analysis

San Sebastian Weather on September 25 — Best Time to Visit?

Based on 30 years of historical data, we have the answer.

cloudy

21.2°C

High

14.4°C

Low

31%

Rain

☀️ Feels like 21.4°C

partly-cloudy-day
YES, GOOD CHOICE
Peak Season

September 25 is generally a great time to visit San Sebastian. While there is a slight chance of rain (31%), showers are usually brief. Expect comfortable 21°C weather. Expect a bustling atmosphere in San Sebastian right now—this is when the city truly comes alive with visitors.

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 25

"Mild & Comfortable. Expect average highs of 21.2°C. 31% chance of rain."

What to Wear in San Sebastian in September

Based on historical data for September 25, San Sebastian typically experiences temperatures between 14.4°C and 21.2°C. We recommend packing light jacket, long pants, 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

View Guide

Smart Suitcase

  • Light Jacket
  • Long Pants
  • Umbrella

Average High

extreme-hot

21.2°C

Daytime Peak

Average Low

extreme-cold

14.4°C

Nighttime Low

Feels Like

partly-cloudy-day

21.4°C

☀️ Feels accurate

Rain Chance

rain

31%

Avg 2.3mm if it rains

Cloud Cover

cloudy

59%

Overcast

Pressure

pressure

1018 hPa

Medium volatility

San Sebastian Weather Conditions & UV Index

Weather Confidence

30-year variance analysis

74%Reliable

Based on 10 years of data

Temperature
±3.9°CModerate
Precipitation
16-60%Moderate

Weather is generally predictable, but pack for minor variations. A light backup layer is recommended.

Sun Exposure

UV Index & Safety Guide

2.6Low
036811+

Protection Needed

SPF 15 for extended outdoor time

Time to Sunburn

Type I-II

🔴 31 min to burn

Type III-IV

🟡 47 min to burn

Type V-VI

🟢 78 min to burn

UV estimate based on latitude, season & cloud cover. Actual UV may vary.

Outdoor Comfort

How pleasant is it outside?

80Excellent
TemperatureWarm
HumidityMuggy
WindLight Breeze

Dew Point

17.4°C

Noticeable

Heat Stress

Low

No heat warning

😊 Best outdoor time:
Any time during daylight hours

Marine Conditions

Water Temp
21.1°C
🏊 Swimming Pool
Avg daily surface temperature
Surf Conditions
1.16m
🌊 Fun Waves
Max daily wave height
Advisories

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

06:59

☀️ Noon

13:00

🌇 Sunset

19:02

⏱️ Daylight

12h 3m

Golden Hour
Morning06:59 - 07:37
18:24 - 19:02Evening

Wind Speed

wind

14.1 km/h

Gentle breeze

Sunshine

clear-day

9.1 hrs

Direct Sun (Cloud-free)

Humidity

humidity

79%

Humid / Damp

Travel Intelligence

Exclusive flight analytics & health data for San Sebastian

Smart Flight Estimator

Airport-to-Airport Logistics

unlock smart flight estimates

Add your home location in settings to see airport details.

Travel Health & Safety in San Sebastian

Travel Comfort Index

Real-time tourism conditions

Weather Quality

⛅ Good

75/100

Tourist Crowds

🟡 Busy

85/100

Price Level

💰💰💰 Expensive

90/100

Health & Wellbeing

Meteo-Health Forecast

85Score
Atmospheric Pressure1018 hPa
Volatility:Medium
Migraine RiskMedium

Moderate fluctuations. Some sensitivity possible.

Joint Pain RiskLow

Weather unlikely to affect joint pain.

Fishing IndexFair

Moderate fish activity expected.

Air Quality Forecast
35AQI
Good
PM2.5 Concentration5.2 µg/m³

Air quality is excellent. Perfect for outdoor activities.

Regional Safety Profile

Low

Seismic Activity

Rare minor tremors. Buildings are earthquake-resistant.

Total events (30y):15
In Sep (30y):3
Last in Sep:2004-09-30
💡 Very rare tremors. Standard travel precautions apply.
"According to 30YearWeather's analysis of 30 years of NASA satellite data, San Sebastian on September 25 averages 21.2°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

Loading chart...

Hall of Fame

Records from last 10 years

Hottest
2021
26.7°C
Coldest
2018
10.2°C
Rainiest
2020
32.5mm

Better Alternatives Nearby

Consider these dates within ±7 days

💡 Moving your event by a few days could significantly improve weather conditions

Compare Other Cities

Same date (September 25) in other destinations

🌍 Explore the same date in different destinations around the world

📍 Is San Sebastian Worth Visiting on September 25?

Planning a trip to San Sebastian on September 25? 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 21.2°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 21.1°C (swimming pool). Wave conditions are generally fun waves with heights around 1.16m.

📊 Historical Extremes: The hottest September 25 recorded in the last 30 years saw temperatures hit 26.7°C in 2021, while the coldest dropped to 10.2°C in 2018.

San Sebastian Weather FAQ