Cascais Weather in December
December in Cascais brings moderate temperatures, with highs of 17°C (63°F) and nights dropping to 13°C (55°F). Rainfall is on the higher side this month, averaging around 91 mm (3.6 in), so keep a rain jacket handy.
Rainfall in Cascais in December
On average, there are about 14 days with rain during this month, averaging 91 mm (3.6 in). Expect a fairly normal spread of rainfall this month, with no particular pattern of very heavy or very persistent showers.
Temperature in Cascais in December
Cascais in December gets highs of 17°C (63°F) during the day and drops to 13°C (55°F) at night. Conditions are often most pleasant around the middle of the day. Nights drop to around 13°C (55°F), which is noticeably cooler than the daytime. A light jacket for the evening is a sensible addition, and the cool nights tend to make sleeping comfortable.
Sunshine in Cascais in December
You can expect a moderate amount of sunlight, with approximately 162 hours. This means a pleasant mix of sun and overcast.December in Cascais has its charm, but if you're looking for destinations with pleasant temperatures and sunny skies, our weather planner can help you explore other options in the world.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Portugal, check out our Cascais's climate page.
Cascais Temperature in December
Min Temperature
13°C (55°F)
Max Temperature
17°C (63°F)
Chance of Rain
47%
Precipitation
91 mm (3.6 in)
Rainy days
14 days
Humidity
81%
Sunshine
162 hours
Percentage Sunshine
55%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Cascais typically stay consistent throughout December, with daily highs averaging around 17°C (63°F). Nights are cool, with lows around 9°C (48°F).
Average temperatures in December
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in December
Historical weather for Cascais in December
Browse day-by-day weather records for Cascais spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Cascais historical weather extremes in December
According to our 49 years of weather records for Cascais, the following extremes were recorded between 1976 and 2025.
- Cascais recorded its highest December temperature of 23°C (73°F) on December 2, 1985.
- The coldest December day was on December 20, 2009, with a maximum of 8°C (46°F).
- The coldest night in December in Cascais was on December 5, 1998, with a minimum of -1°C (30°F).
Best Places in Portugal in December
Find out more about the weather in Portugal and which places have the best travel conditions in this month. See all of Portugal in December →
perfect weather
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What to Wear in Cascais in December
Pleasant temperatures in December mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Prepare for significant rainfall with proper waterproof clothing and shoes. It won't hurt to bring your sunglasses along, as you'll see some sunny periods.What To Do in Cascais in December
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Portugal, check out our Cascais's climate page.
Temperature Rainfall Sunshine Humidity
See the full Cascais climate overview or explore weather in Portugal.
