- Climate Type
- Mediterranean with Atlantic influence
Updated July 2026 · Sources cited: weather-and-climate.com, cascais-portugal.com
Good to know
Good to Know
- Summer crowds and prices peak in July–August. June and early September offer warm weather with fewer tourists.
- Beach season is reliably May through end-September, though water remains cool year-round.
- April is notoriously wet ('Em Abril, águas mil' — in April, a thousand waters); expect intense downpours.
- Winter weather is unpredictable: mix of clear days and solid rain, often grey and damp. Humidity makes 15°C (59°F) feel much colder.
- Strong Atlantic winds common, especially at exposed beaches like Guincho.
- Annual rainfall is moderate (624 mm), but highly seasonal; rain falls as heavy Atlantic fronts in winter, not steady drizzle.
- The town spares visitors the interior heat of Portugal but retains Atlantic chill; pack layers.
- If visiting for cultural activities, museums, and dining, winter is pleasant; beaches unsuitable Dec–Feb.
Rainfall
- Dry Season
- June–September (often <5 mm/month)
- Wet Season
- Late October–February; peaks November–December
Driest Month
- Month
- July
- Rainy Days
- 2
- Rainfall Mm
- 3.1
- Rainfall Inches
- 0.1
Wettest Month
- Month
- November
- Rainy Days
- 13
- Rainfall Mm
- 95
- Rainfall Inches
- 3.7
Snowfall
- Occurs
- No
- Note
- Extremely rare or nonexistent due to mild winter temperatures and Atlantic moderation
Sunshine
- Peak Month
- July
- Minimum Month
- December
- Annual Total Hours
- 2500
- Peak Hours Per Day
- 12.8
- Minimum Hours Per Day
- 5.4
Best Months
- Months
- May to October
- Characteristics
- Warm, dry, sunny. Peak tourism June–August. Beach-suitable May–end September.
- Rainfall Range Mm
- 3–95
- Temperature Range Celsius
- 18–22
- Temperature Range Fahrenheit
- 18–22
Peak Season
- Months
- July and August
- Temperature Peak Celsius
- 22
- Temperature Peak Fahrenheit
- 72
- Notes
- Busiest, most expensive. July marks Portuguese school holidays start; August brings foreign tourists.
Temperature
Coldest Month
- Month
- February
- Daytime Celsius
- 16
- Nighttime Celsius
- 12
- Daytime Fahrenheit
- 61
- Nighttime Fahrenheit
- 54
- Note
- Damp sea air makes it feel colder than recorded
Warmest Month
- Month
- August
- Daytime Celsius
- 22
- Daytime Fahrenheit
- 72
- Note
- Official shade temperature; feels warmer in direct sun
Climate Type
Mediterranean with Atlantic influence
Worst Months
- Months
- November to February (wet season); April (brief intense downpours)
- Characteristics
- Unpredictable, damp, grey. Winter may have days of solid rain. Atlantic fronts common.
- Rainfall Range Mm
- 95–123
- Temperature Range Celsius
- 10–16
- Temperature Range Fahrenheit
- 10–16
Sea Conditions
- Warmest Month
- August
- Warmest Celsius
- 19
- Warmest Fahrenheit
- 66
- Water Temperature Year Round Celsius
- 15–19
- Water Temperature Year Round Fahrenheit
- 15–19
- Note
- Chilly year-round; Atlantic influence. Most casual swimmers find it bracing; wetsuits common even summer.
Year Round Overview
- Average Annual Rainfall Mm
- 624
- Average Annual Temperature Celsius
- 19
- Average Annual Temperature Fahrenheit
- 66
- Notes
- Consistent year-round; maritime moderation prevents temperature extremes. High humidity throughout, especially winter.
AI-generated estimateData refreshed July 2026
Sources cited for this category
These are the sources cited in this climate & weather research for this city. Individual figures may not each trace to one of them.
More About Cascais
Data last updated July 2026 · Verify anything important.