Does this passage describe the weather or the climate?
The air pressure is often low in Copenhagen, Denmark.

 - climate
 - weather
Read the text carefully.
The air pressure is often low in Copenhagen, Denmark.
Air pressure is caused by the weight of the air in the atmosphere. When the air pressure is low, the sky is usually cloudy.
The passage tells you about the usual air pressure in Copenhagen. It does not describe what the weather is like on a particular day. So, this passage describes the climate.