The Earth has two hemispheres, divided by the equator. The equator is an imaginary line that is exactly midway between the North Pole and the South Poles, encircling the entire earth. This line creates two equal-sized halves of the Earth, referred to as hemispheres. The Northern Hemisphere is north of the equator, while the Southern Hemisphere is south of it. The continents mostly reach across the hemispheres, but only two -- Europe and North America -- are entirely within the Northern Hemisphere.
Europe and North America
Only Europe and North America are entirely contained within the boundaries of the Northern Hemisphere. North America's southernmost boundary is at the Isthmus of Panama, which is above the equator. This puts North America entirely in the Northern Hemisphere. Europe's southernmost borders are along the Black Sea and Mediterranean Sea, which also puts its boundaries well above the equator. Europe, like North America, is therefore situated entirely within the Northern Hemisphere, because none of its boundaries are south of the equator.