SeasonMapCascais weather in May
Portugal
May in Cascais: nice, a little rain, with clean air — an excellent time to visit.
#5 of 12 months in Cascais · #623 of 1383 destinations to visit in May · comfort 82/100 (tier A)
Updated September 2026 · climate normals from ERA5 reanalysis
Traveller notes on Cascais in May
Notes from nearby Lisbon (24 km away)
Cascais doesn't have its own notes for May yet — these are about Lisbon, close enough to share the season.
May is the one I keep coming back for. Mid-20s by day, cool enough at night for a jacket on the Alfama miradouros, and the jacarandas go purple around Praça do Príncipe Real toward the end of the month. Tourist crowds are already real but the Atlantic hasn't warmed up yet — swimming is for August.
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 — May
| Daytime high | 22°C / 71°F | 😎 nice |
|---|---|---|
| Nighttime low | 15°C / 60°F | |
| Feels like (high) | 22°C / 72°F | |
| Sea temperature | 17°C / 62°F | 🧊 bracing |
| Rainfall | 35 mm / 1.4 in | 🌦 some rain |
| Rainy days | 5 days | |
| Humidity | 75% | 💦 very humid |
| Dew point | 12°C / 54°F | |
| Sunshine | 12.4 h/day | |
| Daylight | 14.3 h | |
| Wind | 24 km/h / 15 mph | |
| Air quality (US AQI) | 48 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Cascais in May
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.
Shoulder seasonschool holidays in 4 of the markets that fill it, an ordinary month(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
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 May — FAQ
- Is May a good time to visit Cascais?
- May in Cascais: nice, a little rain, with clean air — an excellent time to visit. It ranks #5 of 12 months for Cascais on SeasonMap's comfort score (82/100).
- What is the weather like in Cascais in May?
- In May, Cascais averages a daily high of 21.9°C and a low of 15.3°C, with about 35 mm of rain over roughly 4.6 rainy days.
- What is the air quality in Cascais in May?
- Cascais has a mean US Air Quality Index of about 48 in May.
Other months in Cascais
Compare Cascais in May
Warmer or cooler than Cascais in May
Similar destinations in Southern Europe — May
Within 300 km: Lisbon's Jacaranda bloom around 15 May – 20 Jun, and Évora's Cork stripping around 15 May – 31 Aug.