Cascais Temperature by Month

The average annual maximum temperature in Cascais, Lisbon Region, Portugal is 19°C (66°F), with little variation between seasons. This page covers monthly averages, day-night differences, and how Cascais compares to cities worldwide.

The temperature in Cascais changes very little across the seasons, maintaining a similar climate throughout the year. Maximum daytime temperatures range from a moderate 16°C (61°F) in January to a comfortable 22°C (72°F) in August. Nighttime lows range from 18°C (64°F) in August to 12°C (54°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in Cascais by month:

Daily lows are most common between 4 AM and 6 AM. By 3 PM temperatures reach their daily high, driven by peak solar heating. August, the warmest month of the year, receives 355 hours of sunshine.

The chart below shows the average temperature throughout the year:

Cascais's average annual maximum temperature is 19°C (66°F). To put that in context, here's how it compares to a few well-known destinations:

Athens, Greece sits at 23°C (73°F) on average, with hot dry summers and mild winters characteristic of the Mediterranean.

On the cooler end, Oslo, Norway averages just 10°C (50°F) annually, with pleasant summers but long, cold winters.

San Francisco, USA averages 19°C (66°F) annually, but with little seasonal variation, summers are often cool and foggy, winters mild.

Perth, Australia averages 25°C (77°F) annually, with a classic Mediterranean climate, hot dry summers and mild wet winters.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In Cascais, January is the coolest month, with average highs of 16°C (61°F) and humidity around 82%, considered very high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

Seasonal temperature shifts influence more than just how warm it feels, they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.

Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in Cascais this rarely lasts long on the ground.

For more on Cascais's weather, including monthly rainfall, sunshine hours, and humidity, visit our Cascais climate page.