December weather forecast
Cascais, Portugal

Concluding the year, December in Cascais Portugal reverts to cooler temperatures and turns considerably wetter compared to November. A total of 120mm (4.72") of rainfall is marked, matching almost with the year's beginning weather pattern. The shorter days and cooler temperatures infuse a tranquil winter atmosphere. Leading into January, the forecast suggests a continuance of relatively mild temperatures with high precipitation frequency, completing the yearly weather cycle.

Temperature

December's onset in Cascais records a minor alteration in the average high-temperature to a still refreshing 15°C (59°F) from November's 17°C (62.6°F). The average low-temperature of 9°C (48.2°F) is witnessed in Cascais during December.

Rainfall

In Cascais, in December, it is raining for 14 days, with typically 120mm (4.72") of accumulated precipitation. In Cascais, Portugal, during the entire year, the rain falls for 116 days and collects up to 841mm (33.11") of precipitation.

Sea temperature

In Cascais, Portugal, the average seawater temperature in December is 16.6°C (61.9°F).
Note: For most, swimming in 16.6°C (61.9°F) is not a pleasant experience. As the temperature falls from 21°C (69.8°F) to 15°C (59°F), controlling one's breathing becomes more difficult.

Daylight

December has the shortest days of the year, with an average of 9h and 30min of daylight.
On the first day of the month, sunrise is at 07:37 and sunset at 17:16. On the last day of December, sunrise is at 07:55 and sunset at 17:26 WET.

Sunshine

January, February, November and December, with an average of 5h of sunshine, are months with the least sunshine in Cascais.

UV index

The months with the lowest UV index in Cascais are January and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV rays for the average person.
Note: The maximum UV index of 2 during December leads to these instructions:
Children, infants, and individuals with sensitive skin should be constantly protected from extended sun exposure. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades.