The climate in the National Park, which lies on the western edge of Germany, is strongly influenced by the Atlantic. The relatively mild winters and relatively cool summers with high levels of precipitation are characteristic of the climate here.
As our climate is dominated by westerly winds, most rain showers occur when the clouds meet the west-facing slopes. There is less precipitation for the other side of the ridges, i.e. the areas lying to the east of the slopes in the slipstream. The level of elevation also plays of role: in order to pass over high ridges, the air must rise, which in turn causes it to cool down more – this causes more precipitation to be released as the air passes higher altitudes. These two factors cause considerable differences to the amount of precipitation within the relatively small area of the National Park. In the southwesterly part of the National Park, it rains an average of 1,000 to 1,200 millimetres per annum; in the lower, northern area of Heimbach (northeast) there is, by contrast, just approx. 600 to 800 millimetres of rain.
The average annual temperature is affected in a similar way: it is around 6.5° C at high altitude and around 8° C in the lower regions. The vegetation period on the elevated areas near Wahlerscheid in the south is around 130 days – by contrast, the plants in the northern part near Nideggen have warm temperatures for an average of 30 days longer each year.