San Sebastian — Current Water Temperature, Annual Trends and Forecast
This page provides information on the current water temperature in San Sebastian, trends, monthly ranges and the forecast for the coming days.
Current Water Temperature
Water Temperature in San Sebastian today is 19°C.
Water Temperature: Daily Trends, Historical Records, and Forecast
⚠️ As of today, the minimum water temperature ranges from 65°F (18°C) to 68°F (20°C). This is already quite warm water, which is ideal for most people. Swimming becomes comfortable, and prolonged stays in the water do not cause discomfort. This temperature is perfect for family trips and for those who prefer warmer water. It is also comfortable for water sports such as surfing or swimming. It is important to note that these swimming tips and recommendations apply only in good weather. When the air temperature is below 68°F (20°C), and sometimes even below 77°F (25°C), swimming can be unpleasant even with relatively high water temperatures.
Water Temperature Chart Over the Last 30 Days
Table of Daily Sea Temperature Data
| Date | Current | Average | Forecast |
|---|---|---|---|
| OCT 3 | 21.1°C | 14.0°C | |
| OCT 4 | 20.6°C | 14.0°C | |
| OCT 5 | 20.4°C | 14.0°C | |
| OCT 6 | 20.4°C | 14.0°C | |
| OCT 7 | 19.9°C | 14.0°C | |
| OCT 8 | 20.3°C | 14.0°C | |
| OCT 9 | 19.5°C | 14.0°C | |
| OCT 10 | 18.9°C | 14.0°C | |
| OCT 11 | 14.0°C | 18.8°C | |
| OCT 12 | 14.0°C | 18.5°C | |
| OCT 13 | 14.0°C | 18.3°C | |
| OCT 14 | 14.0°C | 18.0°C | |
| OCT 15 | 14.0°C | 17.8°C | |
| OCT 16 | 14.0°C | 17.5°C | |
| OCT 17 | 14.0°C | 17.3°C |
* Current - Actual water temperature value
** Average - Average water temperature on this day in recent years
*** Forecast - Our water temperature forecast
Actual nearshore water temperatures may fluctuate by several degrees from the reported values, especially following heavy rainfall or extended periods of strong winds. Certain wind patterns can cause colder, deeper waters to rise and replace the sun-warmed surface water, leading to noticeable variations.
Our forecast is based on a proprietary mathematical model that considers real-time water temperature changes, historical trends, key weather patterns, wind strength and direction, and air temperature specific to each region. Additionally, we incorporate data from other resorts to enhance accuracy.
Monthly Water Temperature Range (Min, Max & Average)
| Month | Min | Avg | Max |
|---|---|---|---|
| January | 4°C | 7°C | 11°C |
| February | 4°C | 8°C | 12°C |
| March | 7°C | 10°C | 13°C |
| April | 9°C | 13°C | 17°C |
| May | 9°C | 15°C | 21°C |
| June | 13°C | 19°C | 25°C |
| July | 14°C | 20°C | 26°C |
| August | 15°C | 20°C | 26°C |
| September | 13°C | 18°C | 23°C |
| October | 10°C | 14°C | 17°C |
| November | 8°C | 13°C | 17°C |
| December | 4°C | 8°C | 12°C |
San Sebastian: Weather Forecast
October 11
October 12
October 13
October 14
October 15
October 16
Location & Local Information
San Sebastián (Spanish: San Sebastián), on the Bay of Biscay in the Basque Country, is known for its sheltered La Concha bay and open coastal waters rather than inland lakes. Sea-surface temperatures around the city vary by season: winter months typically range about 11–14 °C (52–57 °F), spring about 12–16 °C (54–61 °F), summer peaks near 18–22 °C (64–72 °F), and autumn generally falls to 15–18 °C (59–64 °F). These figures are approximate averages; local factors such as tides, wind and upwelling can cause short-term fluctuations. Water is usually coolest from late winter into early spring and warmest in July and August.
Swimming is permitted and popular at main beaches like La Concha and Ondarreta, with a formal bathing season when lifeguards, water-quality monitoring and flag systems are in place. Outside the official season people still swim, but colder temperatures, stronger currents and variable weather make wetsuits advisable and safety precautions more important. Water quality is regularly tested and generally meets bathing standards, which is why municipal authorities maintain facilities and patrols during high season. Visitors should heed local signage and lifeguard advice because tides, surf and occasional marine life can affect conditions.