- Temperature
- Feels like
- Rain
- Wind
- Sea water
- Waves
- Updated
Sea water: 20.4°C, cooling to around 19°C over the coming days
Waves: 2.5m
At 20.4 °C the water in Praia Grande is pleasant for swimming by Atlantic standards.
Sunrise: 07:03 · Sunset: 20:14 · Day length: 13h 11m
| Day | Sea water | Waves |
|---|---|---|
| Friday 28/08 | 20.4 °C | 2.5 m |
| Saturday 29/08 | 20.2 °C | 2.2 m |
| Sunday 30/08 | 20.7 °C | 1.5 m |
| Monday 31/08 | 20.3 °C | 1.6 m |
| Tuesday 01/09 | 18.8 °C | 1.6 m |
| Wednesday 02/09 | 17.1 °C | 1.2 m |
| Thursday 03/09 | 18.9 °C | 1.1 m |
| Month | Average water |
|---|---|
| January | 15.6 °C |
| February | 14.9 °C |
| March | 14.9 °C |
| April | 15.9 °C |
| May | 16.2 °C |
| June | 17.5 °C |
| July | 17.1 °C |
| August | 16.7 °C |
| September | 16.7 °C |
| October | 18.3 °C |
| November | 17.8 °C |
| December | 16.1 °C |
Monthly averages for 2022–2025.
This page shows the water temperature at Praia Grande today and over the next seven days, so you can pick the best beach day before you go.
Sea temperature moves much more slowly than air temperature. A hot afternoon does not warm the ocean, and a windy day can cool it fast. Checking the water itself is the only reliable way to know what to expect.
Praia Grande is a wide beach under cliffs on the Sintra coast, with dinosaur footprints preserved in the rock face above it and a large seawater pool at the southern end. The bay is open to the west and takes the full Atlantic swell, which is why it hosts bodyboard competitions. Exposure plus summer upwelling keeps the water around 16.7 °C in August, and the seawater pool is the usual answer for anyone who wants a longer swim.
The water is warmest in October, averaging 18.3 °C, and coldest in February at 14.9 °C. On the west coast the peak arrives late, in early autumn, because summer upwelling keeps pulling cold deep water to the surface.
The ocean gains and loses heat far more slowly than land, so it runs months behind the seasons. On top of that, the summer northerly wind pushes surface water offshore and draws cold deep water up in its place, which is why a heatwave on land so often coincides with a colder sea.
The waves are the attraction, with a beach break that draws bodyboarders and hosts competitions through the year. For a calmer swim there is the large seawater pool at the southern end, filled from the sea and far more forgiving than the shore break. The cliff above holds a set of dinosaur footprints, and the walk up to see them takes only a few minutes.