The mountain ranges surrounding the southeast of the county act as a barrier to the warm, damp air coming in off the sea, just over 20 km away as the crow flies. And the Montsant massif, to the northwest, blocks the cold northerly winds and smoothes out the harsh edges to the continental climate in the west of Catalonia. This mountainous barrier also means that there is very little rain over the course of a year: the average annual rainfall is 500 l/m².

Porrera has long, dry, hot summers with daytime temperatures that can reach 40 ºC (104 ºF). At night, however, temperatures drop dramatically to as low as 12 ºC (54 ºF), which is the average winter temperature.

Winters in the Priorat are short, dry and cold, and daytime and nighttime temperatures can vary significantly. Spring and fall, however, are wetter months with milder temperatures, although the wind can often pick up and bring raging storms.

This large variation in temperature makes the fruit ripen slowly, optimizes the tannins and concentrates all the aromatic potential in the berries.

However, each estate, each parcel, and even each row of vines has its own microclimate determined by its altitude, orientation, terrain, and surroundings.

Merum Priorati makes the most of its range of microclimates to bring the personality and complexity of its wines to the fore.