San Sebastian in Summer
In summer (June, July and August), San Sebastian sees average daytime highs around 21°C and overnight lows near 16°C, with 264 mm of rain over about 38 wet days across the season. It is the warmest season of the year and the driest season of the year.
Over the season highs climb from about 19°C in early June to 22°C by late August. The sky is clear or mostly clear about 30% of the time across summer, and the air most often feels humid.
Summer is San Sebastian's best season of the year to visit on our travel score. For the whole year in context, see San Sebastian's year-round climate.
- Avg daytime high
- 21°C
- warmest season of the year
- Avg overnight low
- 16°C
- Rainfall
- 264 mm
- 38 wet days
- Avg wind
- 10 km/h
- Travel score
- 6.2
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in San Sebastian in Summer
Over the season highs climb from about 19°C in early June to 22°C by late August.
A typical summer day in San Sebastian reaches about 21°C and drops to 16°C overnight. The warmest of the three months is August, the coolest June.
San Sebastian weather by month
How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 10° / 6° | 135 | 15.4 | 1.2 | 9.2 | 2.1 |
| Feb | 11° / 6° | 122 | 14 | 1.9 | 10.2 | 2.3 |
| Mar | 13° / 7° | 115 | 13.9 | 0.9 | 11.6 | 3.2 |
| Apr | 14° / 9° | 127 | 16.1 | 0.1 | 13.2 | 3.5 |
| May | 17° / 11° | 117 | 15.4 | 0 | 14.5 | 4.8 |
| Jun | 20° / 14° | 93 | 12.7 | 0 | 15.1 | 5.8 |
| Jul | 22° / 16° | 82 | 12.7 | 0 | 14.9 | 6.3 |
| Aug | 23° / 17° | 89 | 12.9 | 0 | 13.8 | 6.5 |
| Sep | 21° / 15° | 96 | 13 | 0 | 12.3 | 6.0 |
| Oct | 18° / 12° | 128 | 14.3 | 0 | 10.8 | 5.2 |
| Nov | 13° / 9° | 170 | 15.7 | 0.2 | 9.5 | 3.3 |
| Dec | 11° / 7° | 138 | 15.1 | 0.8 | 8.8 | 2.4 |
Cloud cover in Summer
The sky is clear or mostly clear about 30% of the time across summer.
Chance of precipitation in Summer
San Sebastian gets around 264 mm of rain over 38 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels humid — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 10 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 15 hours in early June to 13 h 06 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 5.6 kWh/m².
Is summer a good time to visit San Sebastian?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit San Sebastian for sightseeing.
What to pack for San Sebastian in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, San Sebastian sees daytime highs around 21°C and nights near 16°C. Worth packing: light clothes, rain gear and sun protection. About 38 days see rain.
Sea temperature near San Sebastian in Summer
The nearest coast averages about 21°C across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea offshore is warmest in August at about 22°C and coldest in February near 12°C.
It's comfortable for a long swim from Jul 1 to Sep 25 — about 2.9 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 13 | 12 | 13 | 14 | 16 | 19 | 21 | 22 | 21 | 18 | 16 | 14 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Cool | Cool | Refreshing | Refreshing | Refreshing | Cool | Cool | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 13 | Bracing |
| Feb | 12 | Bracing |
| Mar | 13 | Bracing |
| Apr | 14 | Bracing |
| May | 16 | Cool |
| Jun | 19 | Cool |
| Jul | 21 | Refreshing |
| Aug | 22 | Refreshing |
| Sep | 21 | Refreshing |
| Oct | 18 | Cool |
| Nov | 16 | Cool |
| Dec | 14 | Bracing |
UV index in San Sebastian in Summer
Clear-sky midday UV across summer averages around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in San Sebastian peaks around July 15 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 1 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 2 | 5 | 6 | 6 | 8 | 9 | 8 | 5 | 4 | 2 | 1 |
| Level | Low | Low | Moderate | High | High | Very high | Very high | Very high | High | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Low |
| Feb | 2 | Low |
| Mar | 5 | Moderate |
| Apr | 6 | High |
| May | 6 | High |
| Jun | 8 | Very high |
| Jul | 9 | Very high |
| Aug | 8 | Very high |
| Sep | 5 | High |
| Oct | 4 | Moderate |
| Nov | 2 | Low |
| Dec | 1 | Low |
Where is San Sebastian?
San Sebastian sits at 43.3°N, 2.0°W, 17 m above sea level, in Spain. The nearest listed city is Pasaia, 4.0 km away.
Topography around San Sebastian
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Sebastian.
Within 3 km, the terrain around San Sebastian has only modest variations in elevation — a maximum elevation change of 231 m around an average of 45 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 839 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,533 m.
The land around San Sebastian is covered by trees (39%), artificial surfaces (34%) and water (21%) within 3 km, trees (42%) and water (42%) within 16 km, and trees (47%) and water (27%) within 80 km.
Spain travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type C / F
- 230 V · 50 Hz
- Prices
- ≈ 65% of US
- price level, 2025
- GDP per capita
- $38,627
- 2025
- Happiness
- 6.5 / 10
- World Happiness, 2025
- Safe drinking water
- 99%
- of population, 2024
- Homicide rate
- 0.7
- per 100k, 2023
- Road deaths
- 3.9
- per 100k/yr, 2019
- Income group
- High
- World Bank
- English
- Moderate
- EF EPI 540
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for San Sebastian (43.3128°, -1.975°, elevation 17 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.