What hemisphere is Madrid located?

That depends which "Madrid" you are talking about. There are at least 20 cities in the world named Madrid:

• 9 in the United States (western and northern hemispheres)
• 3 in Columbia (western and northern hemispheres)
• 1 in Mexico (western and northern hemispheres)
• 1 in Dominican Republic (western and northern hemispheres)
• 1 in Cuba (western and northern hemispheres)
• 1 in Spain ((western and northern hemispheres. Spain is in both east and west hemispheres, but Madrid is in the western part.)
• 1 in Philippines (eastern and northern hemispheres)
• 1 in Uzbekistan (eastern and northern hemispheres)
• 1 in Sweden (eastern and northern hemispheres)
• 1 in Equatorial New Guinea (eastern and northern hemispheres)