Ondarreta Water Temperature & Swim Forecast
Calmer western neighbour of La Concha.
Warm water with a light chop and a light breeze — great swimming conditions.
Model estimate · modelled, not a buoy measurement. How accurate is this?
Location
Ondarreta on the map, with nearby beaches and live sea temperatures.
7-day forecast
Water, air, waves, wind and UV outlook for the week ahead.
No wetsuit
At 24.6°C the water is warm enough to swim and surf in just a swimsuit or boardshorts.
Recommendation tuned for Ondarreta's current water temperature. Individual tolerance, wind chill, and session length all matter — when in doubt, size up.
Ondarreta swimming conditions summary
- Water temperature
- 24.6°C
- Water feels
- Warm
- Swimmable today
- Yes — comfortable for most swimmers
- Swim conditions score
- 90/100 · Excellent
- Wetsuit needed
- No wetsuit
- Air temperature
- —
- Waves
- —
- Wind
- —
- UV index
- —
- Average sea temperature (September)
- 24.0 °C
- Warmest months to swim
- July, August, September
At 24.6°C the water is warm enough to swim and surf in just a swimsuit or boardshorts. Model estimate. Water, wave, wind and UV values are Open-Meteo marine/weather model estimates, refreshed hourly — not buoy measurements.
Frequently asked questions
Can I swim at Ondarreta right now?
The sea at Ondarreta is currently 24.6°C — excellent swimming conditions. Most swimmers will find the water comfortable when it's above 22°C; below 18°C feels fresh and a wetsuit is recommended.
What will the sea temperature be at Ondarreta next week?
Based on long-term September averages and the latest marine model, expect the sea around Ondarreta to sit close to 21.9°C over the next 7 days. Check the live 7-day chart above for the exact daily outlook.
When is the best month to swim at Ondarreta?
July – August – September are typically the warmest months to swim at Ondarreta, with sea temperatures at their seasonal peak.
Do I need a wetsuit at Ondarreta?
With water currently at 24.6°C: above 22°C no wetsuit needed; 18–22°C a shorty is comfortable for long swims; 14–18°C a 3/2mm full suit; below 14°C a 4/3mm or thicker.
Can I swim at Ondarreta today?
The sea is currently 24.6°C — excellent swimming conditions. Most swimmers will find it pleasant.
- • Located in Basque Country, Spain (Bay of Biscay).
- • Family friendly with calm, accessible water.
- • Live data refreshed hourly from Open-Meteo Marine.
Monthly sea temperature averages
Tap any month to see what to expect — based on regional climatology.
Best time to swim in Ondarreta
The sea in Ondarreta peaks in August, when the water averages around 26°C.
The main swimming season runs from June – October, when surface temperatures stay comfortable for extended sessions.
On average, 5 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.
Shoulder months like May and November are noticeably cooler but often quieter, with fewer crowds and steadier weather.
Outside peak season the water drops toward 16°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable.
The coldest month is typically February at around 14°C, when cold-water swimmers dominate the coast.
Ondarreta sea temperature history
Long-term climatology for Ondarreta shows an annual mean sea temperature of 19°C, ranging from 14°C in winter to 26°C at the summer peak.
The seasonal swing is roughly 12°C between the coldest and warmest month — a useful yardstick when comparing years or checking whether the current sea is running above or below average.
Recent decades have trended slightly warmer at Ondarreta, in line with regional sea-surface temperature records for the wider basin.
Monthly averages below are drawn from multi-decadal climatology and are updated as new observations arrive.
Ondarreta sea temperature: frequently asked questions
What is the warmest month to swim in Ondarreta?
August is the warmest month in Ondarreta, when the sea averages about 26°C. Late-season warmth often persists a few weeks after peak.
When is the sea coldest in Ondarreta?
The coldest month in Ondarreta is typically February, when the water averages around 14°C. Cold-water swimmers and surfers dominate this period.
When can you swim in Ondarreta without a wetsuit?
The main swimming season in Ondarreta runs from June – October — about 5 months a year when the sea sits above 20°C, the level most swimmers describe as pleasant without a wetsuit.
Do I need a wetsuit in Ondarreta?
Outside peak summer the water in Ondarreta drops toward 16°C, so a 3/2mm shorty or full wetsuit makes long swims much more comfortable. In peak months most swimmers go without.
What is the average sea temperature in Ondarreta?
The long-term annual mean sea temperature in Ondarreta is about 19°C, based on multi-decadal climatology of the surrounding waters.
How do I check the current sea temperature in Ondarreta?
The live reading at the top of this page shows the current sea temperature in Ondarreta, updated hourly from marine buoy and satellite data. The 7-day forecast covers water, air, waves, wind and UV for the week ahead.
Year-round sea temperature
Best swim months: Jun – Jul – Aug – Sep – Oct
| Month | Sea | Comfort |
|---|---|---|
| Jan | 15°C | Bracing |
| Feb | 14°C | Bracing |
| Mar | 15°C | Bracing |
| Apr | 16°C | Bracing |
| May | 18°C | Pleasant |
| Jun | 22°C | Warm |
| Jul | 25°C | Warm |
| Aug ⭐ | 26°C | Hot |
| Sep | 24°C | Warm |
| Oct | 21°C | Pleasant |
| Nov | 18°C | Pleasant |
| Dec | 16°C | Bracing |
Nearby beaches
The closest coastline, with live water temperatures.