Yearly & Monthly weather - Cascais, Portugal

The climate of Cascais

Cascais, a mesmerizing coastal town of Portugal, primarily experiences a Mediterranean climate, signified as Csa in Köppen climate classification. This type of climate typically includes hot summers and mild winters, with a fairly consistent level of rainfall throughout the year. Given its geographical proximity to the Atlantic Ocean, the weather of Cascais can be described as maritime, with sea temperatures influencing the overall climate.

Scrutinizing the year-round climate statistics, temperature fluctuations are observed but remain within a comfortable range. The highest average temperatures generally fall between 26°C (78.8°F) and 27°C (80.6°F) during peak summer months, while in the colder months, the lowest these dip is to 8°C (46.4°F) to 9°C (48.2°F). Rainfall patterns show some variability, peaking in the colder months, tumbling to almost insignificant levels during the summers. The town experiences its most significant rainfall from 122mm (4.8") to 123mm (4.84") during winter, dropping drastically to a mere 7mm (0.28") to 8mm (0.31") in the middle of the year.

The town basks in extended daylight hours during summer, reaching up to 14.8 hours of daylight in June. Conversely, the winter months, December and January, enjoy a shorter day length of 9.5 to 9.8 hours average. With regards to sunshine, from 11 hours in July and August to just about 5 hours in the cooler months, Cascais seems to enjoy a varied palette of sunshine availability.

The best time to visit Cascais

Taking the overall climate and specific weather conditions into account, the most favourable time to visit Cascais is during the late spring and early summer months. From May to July, the daytime temperatures range from 21°C (69.8°F) to 26°C (78.8°F), ideal for exploring the town’s attractions. The town also enjoys an impressive 9 to 11 hours of sunshine during these months. The rainfall is exceptionally low during this period of the year, making outdoor activities and sightseeing more enjoyable. The UV index during this time is between 8 and 9, suggesting a need for suitable sun protection.

The worst time to visit Cascais

Winter months, specifically December and January, might not present the most enjoyable climate conditions for tourists in Cascais. During these months, temperatures drop to a low range of 8°C (46.4°F) to 9°C (48.2°F), combined with comparatively high levels of rainfall averaging 120mm (4.72") to 123mm (4.84"). This could potentially hinder outdoor activities. The daylight hours are considerably less compared to the rest of the year, and the town basks in the least amount of sunshine, roughly around 5 hours per day.

Spring weather in Cascais

Spring is marked by a transition from the colder to warmer months, with temperatures steadily climbing from 14°C (57.2°F) in March to 21°C (69.8°F) in May. This season witnesses a marked reduction in rainfall, declining from 78mm (3.07") in March to a noticeably lower 46mm (1.81") by May. The lengthening daylight hours and increasing sunlight duration provide relief from the grey and overcast winter months. The UV index also rises, reaching a moderately high value of 6 by the end of spring, indicating increased sun strength.

Summer weather in Cascais

The summer in Cascais typically spans from June to August when the temperatures soar and reach their peak. Daytime temperatures range from 24°C (75.2°F) in June to 27°C (80.6°F) in August, offering the perfect warm seaside conditions. The sunshine hours maximize during this period, reaching an impressive 11 hours per day. Rainfall is scarce, reaching its annual low from 7mm (0.28") to 8mm (0.31"), making it the ideal time for beach activities and exploring. However, visitors should be mindful of the UV index, which peaks at 9 during this time, signifying a substantial risk of harm from unprotected sun exposure.

Autumn weather in Cascais

Autumn sees Cascais transitioning from the scorching summer to cooler temperatures, with a marked decrease from 26°C (78.8°F) in September to 17°C (62.6°F) by November. Rainfall begins to increase, jumping from 31mm (1.22") in September to 122mm (4.8") by November. With reduction in daylight hours and sunshine duration, the town starts to brace up for the approaching winter. Despite the cooling temperatures, sea temperatures remain fairly warm, averaging between 19.8°C (67.6°F) and 18.1°C (64.6°F) throughout the season.

Winter weather in Cascais

The winter season is characterized by the lowest temperatures and the highest precipitation levels. With temperatures ranging from 8°C (46.4°F) in January to 15°C (59°F) in December, winters are relatively mild compared to many other European locations. Rainfall is the highest during these months, with December witnessing about 122mm (4.8"). The daylight hours are the shortest, and sunshine hours dwindle to the annual minimum. Even though sea temperatures drop to 16.6°C (61.9°F) by December, it is still more temperate compared to many other regions and can be preferred for water activities by those with a tolerance for colder water.

Weather in January

January in Cascais, Portugal, boasts cooler, relatively mild conditions, coupled with considerable precipitation. Compared to December, January moderates slightly with average high and low temperatures of 14°C (57.2°F) and 8°C (46.4°F), respectively. Weather in January »

Weather in February

The weather in February in Cascais exudes similar characteristics to January, though slightly warmer and less wet. The ocean tempers the climate, further contributing to the modest increase in comfortable temperatures. Marking an end to Cascais's rainiest period, rainfall measurements decrease to 121mm (4.76"). Weather in February »

Weather in March

Characterized by improved temperatures, Cascais in March paints the first authentic hues of spring, differentiating it distinctly from February. Rainfall exhibits a substantial decline, reducing significantly to 78mm (3.07"). The shift towards spring makes March stand out as a transitional month, promoting growth and color across the charming landscape of the city. Weather in March »

Weather in April

Pursuing milder conditions, the weather in April in Cascais spotlights a welcoming rise in warmth. Reflecting a typical spring climate, the city sees serene days interspersed with rare rainy ones. Showers recorded fall to 70mm (2.76") as the lineage of decreasing rain from March continues. Weather in April »

Weather in May

Boasting substantial sunshine hours, May graces Cascais with the authentic ambiance of spring. The beautiful weather encourages exploration around the city and its captivating ancient heritage. Rainfall continues to decline, plunging to a minimal 46mm (1.81") highlighting a significant shift from the wetter start of the year. Weather in May »

Weather in June

June in Cascais translates into a definitive entrance into summer, breaking away from the milder May days. The fine weather makes it the prime time for outdoor activities, with the city basking in an impressive ten hours of sunshine. Weather in June »

Weather in July

July, amidst searing sunshine and clear blue skies, brings Cascais to the peak of summer. Undisturbed by rainfall, with a meager 7mm (0.28") calculated, the city exudes an atmosphere of endless summer days. High summer temperatures are at their zenith, while the sea temperature reaches a perfect equilibrium, enticing both locals and visitors for a refreshing dip. Weather in July »

Weather in August

August continues the summer season in Cascais, albeit with slightly more balanced weather conditions than July. With just 8mm (0.31") of rainfall observed, the dry and sunny climate remains untamed, providing a stable atmosphere. Weather in August »

Weather in September

Cascais in September boasts slightly milder weather than August while maintaining the city's attractive summer charm. Remaining dry but starting to exhibit the subtle signs of fall, the rainfall increases to 31mm (1.22"). The weather favors outdoor enthusiasts with its still comfortably warm temperatures and gentle sea breezes. Weather in September »

Weather in October

October introduces the city of Cascais to noticeable autumnal changes, with gradually cooler temperatures than those observed in September. Drawing in more moisture, the rainfall jumps to 89mm (3.5"), creating a palpable shift from the drier summer months. Weather in October »

Weather in November

The last month of the autumn, November, is comfortable month in Cascais, Portugal, with an average temperature ranging between min 11°C (51.8°F) and max 17°C (62.6°F). The shift from October to November involves a decrease in the average high-temperature, from an agreeable 22°C (71.6°F) to a comfortable 17°C (62.6°F). Weather in November »

Weather in December

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. Weather in December »

Updated: Feb 2, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What part of the year is the coldest in Cascais?

January, with an average high of 14°C (57.2°F) and a low of 8°C (46.4°F), signifies the coldest month of the year.

What is the rainiest month in Cascais?

January is the month with the most rainfall in Cascais. Rain falls for 15 days and accumulates 123mm (4.84") of precipitation.

How many days does it rain in Cascais?

In Cascais, Portugal, during the entire year, the rain falls for 116 days and collects up to 841mm (33.11") of precipitation.

What is the month with the least sunshine in Cascais?

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

What are the months with the lowest UV index in Cascais?

The months with the lowest UV index are January and December, with an average maximum UV index of 2.

When is the sea coldest in Cascais?

The month with the coldest seawater is March, with an average sea temperature of 15.1°C (59.2°F).

When are the longest days in Cascais?

The month with the longest days is June, with an average of 14h and 48min of daylight.

What are the months with the highest UV index in Cascais?

The months with the highest UV index in Cascais are June and July, with an average maximum UV index of 9.

What is the driest month in Cascais?

July is the month with the least rainfall. Rain falls for 2 days and accumulates 7mm (0.28") of precipitation.

What is the month with the most sunshine in Cascais?

July and August, with an average of 11h of sunshine, are months with the most sunshine in Cascais, Portugal.

What is the warmest month in Cascais?

The month of August sees the average highest temperatures, reaching 27°C (80.6°F) at the peak and 17°C (62.6°F) at the low.

What month is the sea warmest in Cascais?

With an average sea temperature of 19.9°C (67.8°F), September is the month with the warmest seawater in Cascais.

When is Daylight Saving Time (DST) in Cascais?

On Sunday, 27. October 2024, at 02:00, Daylight Saving Time ends, and the time zone changes from WEST to WET. The next Daylight Saving Time starts on Sunday, 30. March 2025, at 01:00, and the time zone reverts from WET to WEST.

What is the month with the shortest days in Cascais?

December has the shortest days of the year, with an average of 9h and 30min of daylight.

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Average temperature
Cascais, Portugal

Average high temperature in January:
14°C
Average high temperature in February:
15°C
Average high temperature in March:
17°C
Average high temperature in April:
18°C
Average high temperature in May:
21°C
Average high temperature in June:
24°C

Average high temperature in July:
26°C
Average high temperature in August:
27°C
Average high temperature in September:
26°C
Average high temperature in October:
22°C
Average high temperature in November:
17°C
Average high temperature in December:
15°C

The warmest month (with the highest average high temperature) is August (27°C).
The month with the lowest average high temperature is January (14°C).

Average low temperature in January:
8°C
Average low temperature in February:
9°C
Average low temperature in March:
10°C
Average low temperature in April:
11°C
Average low temperature in May:
13°C
Average low temperature in June:
15°C

Average low temperature in July:
17°C
Average low temperature in August:
17°C
Average low temperature in September:
17°C
Average low temperature in October:
14°C
Average low temperature in November:
11°C
Average low temperature in December:
9°C

The months with the highest average low temperature are July, August and September (17°C).
The coldest month (with the lowest average low temperature) is January (8°C).

Average rainfall
Cascais, Portugal

The wettest month (with the highest rainfall) is January (123mm).
The driest month (with the least rainfall) is July (7mm).

Average rainfall days
Cascais, Portugal

Average rainfall days in January:
15 days
Average rainfall days in February:
14 days
Average rainfall days in March:
13 days
Average rainfall days in April:
12 days
Average rainfall days in May:
9 days
Average rainfall days in June:
5 days

Average rainfall days in July:
2 days
Average rainfall days in August:
2 days
Average rainfall days in September:
6 days
Average rainfall days in October:
11 days
Average rainfall days in November:
13 days
Average rainfall days in December:
14 days

The month with the highest number of rainy days is January (15 days).
The months with the least rainy days are July and August (2 days).

Average sea temperature
Cascais, Portugal

Average sea temperature in January:
15.8°C
Average sea temperature in February:
15.3°C
Average sea temperature in March:
15.1°C
Average sea temperature in April:
16.3°C
Average sea temperature in May:
17.4°C
Average sea temperature in June:
18.6°C

Average sea temperature in July:
18.9°C
Average sea temperature in August:
19.6°C
Average sea temperature in September:
19.9°C
Average sea temperature in October:
19.8°C
Average sea temperature in November:
18.1°C
Average sea temperature in December:
16.6°C

The best month for swimming (with the highest average sea temperature) is September (19.9°C).
The coldest month (with the lowest average sea temperature) is March (15.1°C).

Average daylight / Average sunshine
Cascais, Portugal

Average daylight in January:
9h and 5min
Average daylight in February:
10h and 5min
Average daylight in March:
12h and 0min
Average daylight in April:
13h and 1min
Average daylight in May:
14h and 2min
Average daylight in June:
14h and 5min

Average daylight in July:
14h and 4min
Average daylight in August:
13h and 4min
Average daylight in September:
12h and 2min
Average daylight in October:
11h and 1min
Average daylight in November:
10h and 1min
Average daylight in December:
9h and 3min

The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).

The months with the most sunshine are July and August (Average sunshine: 11h).
The months with the least sunshine are January, February, November and December (Average sunshine: 5h).

Average UV index
Cascais, Portugal

The months with the highest UV index are June and July (UV index 9).
The months with the lowest UV index are January and December (UV index 2).

Climate and monthly weather forecastCascais, Portugal

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