Praia de Sao Juliao Water Temperature & Swim Forecast
Lisbon Coast family beach.
Mild water with a light chop and a light breeze — good swimming conditions.
Model estimate · modelled, not a buoy measurement. How accurate is this?
Location
Praia de Sao Juliao on the map, with nearby beaches and live sea temperatures.
7-day forecast
Water, air, waves, wind and UV outlook for the week ahead.
Shorty 2mm
At 20.8°C a 2mm shorty keeps surfers warm; lap swimmers can usually skip the neoprene.
Recommendation tuned for Praia de Sao Juliao's current water temperature. Individual tolerance, wind chill, and session length all matter — when in doubt, size up.
Praia de Sao Juliao swimming conditions summary
- Water temperature
- 20.8°C
- Water feels
- Pleasant
- Swimmable today
- Yes — comfortable for most swimmers
- Swim conditions score
- 81/100 · Excellent
- Wetsuit needed
- Shorty 2mm
- Air temperature
- —
- Waves
- —
- Wind
- —
- UV index
- —
- Average sea temperature (September)
- 21.0 °C
- Warmest months to swim
- July, August, September
At 20.8°C a 2mm shorty keeps surfers warm; lap swimmers can usually skip the neoprene. 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 Praia de Sao Juliao right now?
The sea at Praia de Sao Juliao is currently 20.8°C — good 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 Praia de Sao Juliao next week?
Based on long-term September averages and the latest marine model, expect the sea around Praia de Sao Juliao to sit close to 19.6°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 Praia de Sao Juliao?
July – August – September are typically the warmest months to swim at Praia de Sao Juliao, with sea temperatures at their seasonal peak.
Do I need a wetsuit at Praia de Sao Juliao?
With water currently at 20.8°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 Praia de Sao Juliao today?
The sea is currently 20.8°C — excellent swimming conditions. Most swimmers will find it pleasant.
- • Located in Lisbon Coast, Portugal (Atlantic Ocean).
- • 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 Praia de Sao Juliao
The sea in Praia de Sao Juliao peaks in August, when the water averages around 21°C.
The main swimming season runs from July – September, when surface temperatures stay comfortable for extended sessions.
On average, 3 months a year sit above 20°C — the threshold most swimmers describe as pleasant without a wetsuit.
Shoulder months like June and October are noticeably cooler but often quieter, with fewer crowds and steadier weather.
Outside peak season the water drops toward 14°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.
Praia de Sao Juliao sea temperature history
Long-term climatology for Praia de Sao Juliao shows an annual mean sea temperature of 18°C, ranging from 14°C in winter to 21°C at the summer peak.
The seasonal swing is roughly 7°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 Praia de Sao Juliao, 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.
Praia de Sao Juliao sea temperature: frequently asked questions
What is the warmest month to swim in Praia de Sao Juliao?
August is the warmest month in Praia de Sao Juliao, when the sea averages about 21°C. Late-season warmth often persists a few weeks after peak.
When is the sea coldest in Praia de Sao Juliao?
The coldest month in Praia de Sao Juliao is typically February, when the water averages around 14°C. Cold-water swimmers and surfers dominate this period.
When can you swim in Praia de Sao Juliao without a wetsuit?
The main swimming season in Praia de Sao Juliao runs from July – September — about 3 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 Praia de Sao Juliao?
Outside peak summer the water in Praia de Sao Juliao drops toward 14°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 Praia de Sao Juliao?
The long-term annual mean sea temperature in Praia de Sao Juliao is about 18°C, based on multi-decadal climatology of the surrounding waters.
How do I check the current sea temperature in Praia de Sao Juliao?
The live reading at the top of this page shows the current sea temperature in Praia de Sao Juliao, 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: Jul – Aug – Sep
| Month | Sea | Comfort |
|---|---|---|
| Jan | 15°C | Bracing |
| Feb | 14°C | Bracing |
| Mar | 15°C | Bracing |
| Apr | 16°C | Bracing |
| May | 17°C | Bracing |
| Jun | 19°C | Pleasant |
| Jul | 20°C | Pleasant |
| Aug ⭐ | 21°C | Pleasant |
| Sep | 21°C | Pleasant |
| Oct | 19°C | Pleasant |
| Nov | 18°C | Pleasant |
| Dec | 16°C | Bracing |
Nearby beaches
The closest coastline, with live water temperatures.