Day
15 °C
Night
9 °C
Sea
15 °C
Precipitation
85 mm
in month
Rainy days
10 days
in month
Daylight
10 hours
average
Sunshine
5 hours
average
Humidity
81 %
We make the most from 40 years of historical weather data to predict the best weather conditions.
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Cascais, a coastal town in Portugal, boasts a warm climate characterized by its mild weather patterns throughout the year. Daily temperatures in this region typically range from 15 °C (59 °F) in the colder months to the peak of 24 °C (74 °F) during the warmer period in August. The least amount of rainfall occurs in July, with an average of only 1 day expressing precipitation. In stark contrast, November is the month with the highest frequency of rainfall, reaching up to 11 days. Additionally, ocean temperatures fluctuate between 15 °C (58 °F) in the colder months and 19 °C (66 °F) in the month of August. As night falls, temperatures drop to a range between 9 °C (48 °F) in January to 16 °C (60 °F) in the height of summer.
During January, Cascais experiences its lowest daytime temperatures, averaging 15 °C (59 °F), while the sea temperature slightly decreases from the previous month to 15 °C (59 °F). The downturn in the number of rainy days begins, averaging 10 days, and a similar decrease in the total rainfall amount is also evident. Nighttime temperatures reach their lowest at 9 °C (48 °F), and the peak in humidity is recorded at 81 %.
February sees a gentle increase in daytime temperatures with an average of 16 °C (60 °F) in Cascais, while the sea temperature hits its yearly low. February also marks the beginning of a gradual increase in nighttime temperatures. Rainfall continues to decrease when compared to the previous month, and there's a noticeable uptick in the number of cloudless hours.
With the onset of March, both day (18 °C (64 °F)) and night (11 °C (51 °F)) temperatures in Cascais rise progressively. The trend of fewer rainy days continues, now at 7 days, while the total rainfall reduces to 49 mm (1.91 in). As the sun shines brighter, the number of sunny hours increases to 7 hours.
April in Cascais is characterized by further rising temperatures, with daytime averages of 18 °C (65 °F) and nighttime around 11 °C (53 °F). An upturn in the number of rainy days can be noted, averaging 9 days, along with a slight increase in rainfall amounts 58 mm (2.29 in). The hours of sunshine also rise, recorded at 8 hours.
May brings a discernible rise in the sea temperature to 16 °C (61 °F) in Cascais, alongside stable increases in daytime readings that reach 20 °C (68 °F). The downtrend in rainy days descends to 6 days, with a concurrent reduction in rainfall measured at 44 mm (1.73 in). Nighttime warmth climbs as well, averaging 13 °C (55 °F), and the hours of sunshine reach a notable 9 hours.
June witnesses the sea temperature climbing further in Cascais, paralleled by a continuous rise in the daytime temperature peaking at 23 °C (73 °F). Rainfall dwindles to just 15 mm (0.58 in), and there are meager 3 days of rainy days. The increase in hours of sunlight continues to be apparent.
July marks the beginning of the tourist season in Cascais. The sea temperature escalates to 18 °C (65 °F), and daytime temperatures rise to a comfortable 23 °C (74 °F). A minimal number of rainy days, averaging 1 day, coincides with the lowest rainfall levels of 5 mm (0.18 in). An all-time high in the number of hours without clouds is a highlight of this month.
August in Cascais reaches the apex of warmth, with maximum daytime temperatures of 24 °C (74 °F), and sea temperatures also peaking at 19 °C (66 °F). As the tourist and dry seasons approach their zenith, the minimal rainfall conditions persist, and evenings remain comfortably warm with night temperatures hitting 16 °C (60 °F). Minimum humidity levels are recorded at 64 %.
The conclusion of the peak tourist season occurs in September, yet the warm and dry weather prevails in Cascais. A subtle decline in day temperatures is noted, and the rainy days begin to pick up slightly, averaging 4 days. The sunshine hours see a decrease, reflecting the transition towards autumn.
October's climate in Cascais is marked by a further decrease in daytime temperatures to 21 °C (70 °F), while the sea temperature starts its downward trend at 18 °C (65 °F). The rise in the number of rainy days is more pronounced, with an average of 9 days, and rainfall volumes increase to a comparable extent 87 mm (3.41 in). Night temperatures start to drop, paralleling the descent in sunny hours.
November sees a continuation of the cooling trend in both day (18 °C (64 °F)) and sea (17 °C (63 °F)) temperatures in Cascais. The maximum number of rainy days is the norm, averaging 11 days, coupled with the highest volumes of rainfall achieving 109 mm (4.30 in). A decline in the hours of sun is also evident, marking a shift towards the colder months.
As the year winds down in December, Cascais witnesses a further dip in day temperatures, averaging 15 °C (60 °F), while the sea succumbs to a similar cooling pattern at 16 °C (61 °F). Night temperatures continue their gradual decrease, and the minimal sunshine hours reflect the shortening of the days.
In January, nighttime temperatures in Cascais can drop to as low as 9 °C (48 °F), making it the coldest part of the day.
The sea temperature in Cascais reaches its annual minimum in February.
March in Cascais does not typically bring a significant increase in sea temperatures.
April sees an incremental rise in both rainy days and rainfall amount, indicating slightly wetter conditions compared to the previous month.
Expect an ample 9 hours of clear skies and sunshine during the day throughout May.
June promises extended periods of sunshine, contributing to the enjoyable summer weather.
With sea temperatures averaging 18 °C (65 °F), July offers favorable conditions for swimming in Cascais.
Expect the warmest weather in August, with peak sea and air temperatures, ideal for summer holiday activities.
No, September in Cascais experiences only a modest increase in rainy days.
October brings a noticeable increase in both the frequency and volume of rainfall in Cascais.
Yes, November is characterized by the most frequent rainfall, with greater quantities expected.
December brings shorter days, with the shortest daylight hours of the year.