The climate in Cascais during September can be summarized as warm and reasonably dry.
September is in the fall / autumn in Cascais and is typically the 3rd warmest month of the year. Daytime maximum temperatures average around a comfortable 26°C (78°F), whilst at night 17°C (62°F) is normal.
|Daytime temperature||25.6°C 78.1°F|
|Nightly temperature||16.6°C 61.9°F|
|Average temperature||21.1°C 70°F|
|Daily sunshine||9.2 hrs|
|Avg rainfall||31 mm 1.2 ins|
|Rainy days||6 days|
|Sea temperature||20.4°C 68.7°F|
|Windspeed||12.6kph 8 mph|
On average September is the 4th driest month of the year in Cascais with around 31mm 1.2 inches of rain making it a reasonably dry time to visit. This rainfall is typically spread over 6 days, although this may vary considerably.
On the flip side this corresponds to an average of 9.2 hours of sunshine per day.
The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in September 2020.
|Hottest month:||August||26.6°C 79.9°F|
|Driest month:||July||7mm 0.3ins|
|Coldest month:||January||14.2°C 57.6°F|
|Wettest month:||January||123mm 4.8ins|