SeasonMapCascais weather in August
Portugal
August in Cascais: warm, dry, with clean air — an excellent time to visit.
#4 of 12 months in Cascais · #399 of 1383 destinations to visit in August · comfort 86/100 (tier A)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Cascais in August
Notes from nearby Lisbon (24 km away)
Cascais doesn't have its own notes for August yet — these are about Lisbon, close enough to share the season.
August reads fine on paper and is fine — the nortada wind off the Atlantic keeps it from feeling like Seville. What the score can't tell you is that half the city is shut for holidays and every restaurant that stays open is booked. Go for the beach at Costa da Caparica, not the food.
Other months in Cascais
Cascais's forum calls July hot and sunny but not especially humid, typically mid-20s to low-30s°C with a regular Atlantic breeze that helps take the edge off. Regulars flag the sea itself as genuinely cold year-round despite the warm air, and note evenings can turn cool enough for a light jacket even after a hot day.
Add your own note from Cascais's card on the map.
Cascais climate normals — August
| Daytime high | 27°C / 80°F | 🌤 warm |
|---|---|---|
| Nighttime low | 19°C / 66°F | |
| Feels like (high) | 28°C / 82°F | |
| Sea temperature | 16°C / 61°F | 🥶 cold sea |
| Rainfall | 1 mm / 0 in | ☀️ dry |
| Rainy days | 0 days | |
| Humidity | 76% | 💦 very humid |
| Dew point | 16°C / 61°F | |
| Sunshine | 12.2 h/day | |
| Daylight | 13.6 h | |
| Wind | 25 km/h / 16 mph | |
| Air quality (US AQI) | 39 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Cascais in August
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Peak crowdsLisbon's summer coast, Festas do Mar, Summer holidays in Portugal(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Cascais's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherCascais's best weather comes in June, July and September — separate windows, not one continuous season.
Best weatherFair weatherToughest weather
What's on in Cascais in August
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Season
The nortada
15 Jun – 15 Sep · usuallyWind seasonRiskThe north wind gets up most summer afternoons, which is why Guincho belongs to kitesurfers and why the sheltered town beaches fill instead. Mornings are the calm half of the day.
- Holiday
Lisbon's summer coast
1 Jul – 31 AugSchool holidaysCrowdedBook earlyThe Cascais line runs standing-room only at weekends once the schools break, and the town is as much a Lisbon suburb on holiday as a resort. Weekdays are a different place. Source ↗
- Season
Sea at its warmest
20 Jul – 5 Oct · usuallySea warm enoughThe Atlantic upwelling keeps this coast cold well into summer and it only comes round in August and September. The bay beaches are always a little warmer than Guincho.
- Festival
Festas do Mar
20–30 AugMajor festivalCrowdedFree concerts on the bay across the last two weekends of August, closing with the fishermen's procession for Nossa Senhora dos Navegantes. The bay road is shut on concert nights. Source ↗
Nearby, and something's on
Within 300 km of Cascais — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Cascais?
Cascais in August — FAQ
- Is August a good time to visit Cascais?
- August in Cascais: warm, dry, with clean air — an excellent time to visit. It ranks #4 of 12 months for Cascais on SeasonMap's comfort score (86/100).
- What is the weather like in Cascais in August?
- In August, Cascais averages a daily high of 26.5°C and a low of 18.8°C, with about 0.8 mm of rain over roughly 0.3 rainy days.
- What is the air quality in Cascais in August?
- Cascais has a mean US Air Quality Index of about 39 in August.
Other months in Cascais
Compare Cascais in August
Warmer or cooler than Cascais in August
Similar destinations in Southern Europe — August
Within 300 km: Ericeira's Festas da Senhora da Boa Viagem around 5–18 Aug, and Évora's Cork stripping around 15 May – 31 Aug.