- Temperature
- Feels like
- Rain
- Wind
- Sea water
- Waves
- Updated
Sea water: 19.5°C, warming to around 21°C over the coming days
Waves: 1.5m
At 19.5 °C the water in Cascais is fresh. Fine for a dip, but the first minute bites.
| Day | Sea water | Waves |
|---|---|---|
| Saturday 25/07 | 19.5 °C | 1.5 m |
| Sunday 26/07 | 18.3 °C | 1.7 m |
| Monday 27/07 | 17.8 °C | 1.4 m |
| Tuesday 28/07 | 18.9 °C | 1.1 m |
| Wednesday 29/07 | 19.1 °C | 1.0 m |
| Thursday 30/07 | 19.5 °C | 0.9 m |
| Friday 31/07 | 21.0 °C | 1.0 m |
The water temperature shown here comes from marine forecast models with a dedicated ocean grid point for Cascais, updated every day. The table covers 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.
Cascais lies where the Tagus estuary meets the open Atlantic, just west of Lisbon. Summer upwelling keeps the water noticeably cooler than in the Algarve, and it can drop several degrees in a couple of days when the northerly wind blows, so the daily reading matters here.
Usually in September and October. Even then the west coast rarely climbs past 18 to 20 °C, 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.
Once a day, every morning, from marine forecast models. The page shows today's water temperature in Cascais, the outlook for seven days and the wave height for each day.