- Temperature
- Feels like
- Rain
- Wind
- Sea water
- Waves
- Updated
Right now in São Martinho do Porto: clear skies, 20°C, feels like 22°C.
Expect a mostly partly cloudy week in São Martinho do Porto, with temperatures staying fairly steady between 15°C and 30°C.
Daytime highs this week are close to the August average of 23°C.
Sunrise: 07:01 · Sunset: 20:14 · Day length: 13h 13m
Sea water: 20.4°C, cooling to around 18°C over the coming days
Wave height: 2.4m (min 1.0m on 2026-09-03, max 2.4m on 2026-08-28)
São Martinho do Porto water temperature for the next 7 days · Sea temperature along the whole coast
São Martinho do Porto sits inside a near-circular bay shaped like a shell, with a narrow gap in the cliffs as its only opening to the ocean. That gap does the work: the swell breaks up before it gets in, so the water inside is flat and shallow and the beach shelves gently the whole way round. It is one of the safest beaches on the west coast and a long-standing family favourite.
Summers are pleasant rather than hot at 23–26 °C, with the afternoon northerly largely blocked by the surrounding hills. Winter is mild at 14–15 °C, with rain in Atlantic spells. The enclosed bay makes a real difference to the water: it stays calm, and it warms to about 16–17 °C in late summer, noticeably above the open beaches a few kilometres away.
| Month | Min (°C) | Max (°C) | Rainy days |
|---|---|---|---|
| January | 9.1 | 14.5 | 10.6 |
| February | 9.8 | 15.6 | 9.3 |
| March | 10.4 | 16.1 | 12.9 |
| April | 12.1 | 17.6 | 13.1 |
| May | 14.1 | 19.5 | 8.1 |
| June | 16.1 | 20.9 | 8.0 |
| July | 17.3 | 22.5 | 4.2 |
| August | 17.4 | 22.9 | 2.5 |
| September | 16.6 | 22.5 | 5.3 |
| October | 15.4 | 21.1 | 11.0 |
| November | 12.3 | 17.3 | 13.3 |
| December | 10.3 | 15.6 | 12.1 |
Going by São Martinho do Porto's own averages, August is both the warmest and the most balanced month: highs near 23 °C and about 3 rainy days. The wettest is November with 13 rainy days.
Averages for 2016–2025. A rainy day is one with at least 1 mm of precipitation.
August and September, when the bay reaches roughly 16–17 °C. Because the water is shallow and exchanges slowly with the open sea, it warms faster and holds its warmth better than anywhere else on this stretch of coast. Winter brings it back to about 14–15 °C.
It is about as good as the west coast gets. There is almost no wave inside the bay, the bottom shelves slowly, and the promenade runs the length of the sand with cafés, shade and toilets. Lifeguards cover the beach in season. The current picks up near the narrow entrance, so keep away from that end.
Not inside the bay, which is rather the point. Surfers drive a few minutes north or south to the open beaches, including the breaks around Nazaré. In the bay itself the water sports are paddleboarding, kayaking and swimming.