CascaisPhoto: Terry Kearney from liverpool, merseyside · CC0Portugal · Europe
Best time to visit Cascais
Cascais combines easy access to Lisbon with Atlantic air. The sea stays cool even in summer, so the useful signal is the balance of sun, wind and city time. In the 1991–2025 normals, Cascais reaches typical daytime highs of about 23 °C in the strongest candidate month, August. The four selected travel months are June, July, August, September.
Climate decision
Best travel months for Cascais
Top recommendation
Next highest scores
Historical monthly averages, not a weather forecast. Individual days and years can differ substantially.
Latest 5-year values 2021–2025
Average of the five most recent complete years compared with the 1991–2025 climate average.
March · Wet days
11.6 days/month
1991–2025: 9.2 days/month
+2.4 days/month · higher
May · Monthly precipitation
13.6 mm/month
1991–2025: 37.3 mm/month
-23.7 mm/month · lower
October · Mean daily maximum
21.5 °C
1991–2025: 20.6 °C
+0.9 °C · higher
September · Sea temperature
18.9 °C
1991–2025: 18.8 °C
+0.1 °C · similar
July: 0/155 days at or above 30 °C; highest single value 30 °C.
Five-year historical sample, not a weather forecast or long-term climate trend. Individual hot days can be far above the monthly mean.
Annual profile · Rainfall rhythm
Cascais: rainfall separates the travel months
The driest and wettest months are 10.7 rainy days apart. Average daily highs vary by 8.4 °C, so both signals matter when choosing a month.
What matters
A warmer month is not automatically the most reliable. Read the drier windows alongside sunshine, sea temperature and the activity you have in mind.
Fewest rainy days
July · 0.9
Most rainy days
November · 11.6
Most sunshine
July · 9.1 h
Warmest sea
September · 18.8 °C
Month by month
Overall suitability per month. Tap a month for details.
All climate figures compared
The table is the complete accessible data view; the charts below highlight selected patterns.
| Month | Avg high °C | Avg low °C | Rainy days (est.) | Rain mm | Sun h/day (est.) | Humidity % | Wind m/s | Sea °C | Score |
|---|---|---|---|---|---|---|---|---|---|
| January | 15 | 11 | 10 | 69 | 2.9 | 81 | 4.8 | 15 | 44 |
| February | 15 | 11 | 9 | 52 | 4.1 | 80 | 4.8 | 15 | 49 |
| March | 16 | 12 | 9 | 57 | 5.6 | 80 | 4.7 | 15 | 53 |
| April | 17 | 13 | 9 | 52 | 7.3 | 79 | 4.7 | 16 | 58 |
| May | 19 | 15 | 7 | 37 | 8.6 | 79 | 4.6 | 16 | 69 |
| June | 21 | 17 | 3 | 10 | 9.0 | 80 | 4.6 | 18 | 79 |
| July | 23 | 18 | 1 | 3 | 9.1 | 80 | 4.8 | 18 | 82 |
| August | 23 | 18 | 1 | 5 | 8.3 | 81 | 4.5 | 19 | 84 |
| September | 22 | 18 | 5 | 28 | 6.6 | 81 | 4.0 | 19 | 81 |
| October | 21 | 17 | 10 | 76 | 4.5 | 81 | 4.2 | 18 | 66 |
| November | 18 | 14 | 12 | 87 | 3.1 | 81 | 4.8 | 17 | 52 |
| December | 16 | 12 | 11 | 84 | 2.5 | 82 | 5.0 | 16 | 45 |
Climate through the year
Compare temperature, rainy days, sunshine and, for coastal destinations, sea temperature month by month.
Find a place to stay
Where to stay in Cascais
Compare available stays, prices and cancellation terms for Cascais on Booking.com.
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Useful next decisions
Similar destinations
The number is the overall climate score, not a similarity score.
Country and region
Frequently asked questions
When is the best time to visit Cascais?
The strongest climate months are June, July, August, September. Values are historical averages, not a forecast.
Which month has the highest average daily maximum temperature in Cascais?
The average daily maximum temperature in Cascais is highest in August at around 23 °C.
When is the sea warmest at Cascais?
In September, at around 19 °C.