Costa da Caparica is an exception to this rule as it is far less exposed to the cooler ocean currents and is therefore warmer in the summer.
[13] Lisbon's location on the westernmost side of continental Europe makes it much less vulnerable to both heatwaves and coldwaves, though outbreaks of the Saharan Air Layer can sometimes push the temperatures above 40 °C (104 °F) as it happened as part of the 2018 European heat wave, skies were a shade of white due to the extreme concentrations of airborne dust particles.
Foggy mornings are also common in the summer, especially in coastal areas and can bring drizzle which can sometimes be observed early in the day in wet roads and calçadas.
[20] Sunshine and precipitation stack up oppositely with the dullest month being also the rainiest (December) which has around 140-150 total hours.
Despite July having the most sun hours, August is on average the sunniest month with around 80% chance of direct sunlight hitting the ground.
In the Lisbon area, sunshine hours reach their maximum value in the southwestern Setúbal Peninsula (near Cabo Espichel), and their lowest in the Sintra Mountains and parts of the northwest District.
[31] As with the rest of Portugal, ocean temperatures are extremely moderate and cool year-round, only varying 5 °C (9.0 °F) between the coldest and warmest month.
[35][36] Temperature and precipitation variation across various sections of the metropolitan area of Lisbon: Climate in other places in Iberian Peninsula: