Alcobaça, where it's located

The climate of Alcobaça is temperate oceanic, with mild, rainy winters and pleasantly warm, sunny summers.
The city is located in central Portugal, about 10 km (6 miles) from the ocean, where Nazaré is located. In summer, temperatures are generally pleasant, and sometimes even a little cool. There may be some very hot days, but even in these cases, the temperature generally decreases a lot at night.
The average temperature of the coldest month (January) is of 9.7 °C (49 °F), that of the warmest months (July, August) is of 20.3 °C (69 °F). The lowest record (of the 1971/2000 period) is -5.5 °C (22 °F), the highest is 40.8 °C (105 °F). Here are the average temperatures.
Alcobaça - Average temperatures
Min (°C)457810131514131086
Max (°C)151618192124262626221816
Min (°F)394145465055595755504643
Max (°F)596164667075797979726461

Precipitation amounts to 840 millimeters (33.1 inches) per year: so, it is at an intermediate level. It ranges from 10 mm (0.4 in) in the driest months (July, August) to 130 mm (5.1 in) in the wettest (December). Here is the average precipitation.
Alcobaça - Average precipitation
On average, there are around 2,930 sunshine hours per year: therefore, the amount of sunshine is very good. Here are the average sunshine hours per day.
Alcobaça - Sunshine

The sea temperature ranges between 14 °C (57 °F) and 19 °C (66 °F). So, it never becomes warm for swimming. Here are the average sea temperatures.
Alcobaça - Sea temperature
Temp (°C)141414151617181919181715
Temp (°F)575757596163646666646359


Best Time

The best time to visit Alcobaça runs from June to September, since it is the warmest and the least rainy period of the year. July and August are the warmest months, but the heat is rarely excessive, and in addition, they are the driest. However, in September too, the rains are still quite rare. In May, you can go, but cool and rainy days are more frequent.
Even in summer, it's better to bring a sweatshirt, and maybe a light jacket for the evening.