summer is when a hemisphere is tilted towards the sun & the northern hemisphere is a kind of hemisphere of earth ->  northern hemisphere tilts towards the sun in summer  northern hemisphere tilts towards the sun in summer & when a hemisphere is tilted towards the sun , that hemisphere receives more direct sunlight ->  northern hemisphere will receive more direct sunlight in summer  the northern hemisphere is a kind of hemisphere of earth & winter is when a hemisphere is tilted away from the sun ->  northern hemisphere tilts away the sun in winter  northern hemisphere tilts away the sun in winter & when a hemisphere is tilted away from the sun , that hemisphere receives less direct sunlight ->  northern hemisphere will receive less direct sunlight in winter  northern hemisphere will receive more direct sunlight in summer & northern hemisphere will receive less direct sunlight in winter ->  northern hemisphere receives more direct sunlight in summer than in winter  northern hemisphere receives more direct sunlight in summer than in winter & receiving direct sunlight causes objects to become warm -> northern hemisphere will be warmer in summer than in winter