The weather in Estoril is mild enough that you can comfortably vacation here at any time of year. The summers are quite warm, and as days are typically very sunny, it is a good idea to bring sunscreen and other precautions against burning. Rain is very rare between June and August.

Maximum temperatures during the summers average in the low to mid-80s (about 27° or 28°C).  One advantage of the summer is that evenings are warm (usually about 70°F/21°C or higher) and good for socializing, so the night scene in Estoril during the summer is quite good.

During the winter, Estoril does not get too cold. Minimum temperatures in January still stay well above freezing, usually in the high 40s or low 50s (around 8-10°C). However, some sweaters and long pants will come in handy, especially for walks on the beach, where the winds can get rather brisk. If you go into the mountains, also, you will need warmer clothes, as the micro-climate there is a few degrees cooler than the city of Estoril year-round. Try to avoid visiting Estoril during the late fall, as rain is frequent during this season, with showers almost every day. Total rainfall for the year is about 20 inches (50cm).