The climate of this geographical region is mainly temperate and humid oceanic, characterized by a greater frequency of winds from the north. The average annual temperature of the area is 13掳 C and the difference between the maximum temperature of the year (August) and the minimum (January) is 12掳 C. This makes the Cantabrian Region the area with the lowest thermal amplitude in the Iberian Peninsula.
The insolation is 1700 hours of sunshine per year and the average rainfall is 1800 l / m虏 with an average of 150 to 200 rainy days per year.
The ecoregions found on the Cantabrian coast are the Cantabrian mixed forest and the montane forest of the northwest of the Iberian Peninsula.
The main native species of this biome are oak and beech forests, with strongholds of chestnut, birch, yew and holly. However, since the second half of the twentieth century, in some areas (especially in coastal areas), native forests have been replaced by plantations of white eucalyptus and pine for commercial exploitation in the wood and paper industry.