The hemisphere tilted toward the sun receives more direct sun rays. During spring and fall, the equator receives the most direct sun rays. In July and August, months known as summer, the northern hemisphere is tilted toward the sun and receives the most direct rays.
The opposite occurs in December and January, the months of winter. During these months, the southern hemisphere is tilted toward the sun and the northern hemisphere is tilted away, resulting in more less concentrated (diffuse) sunlight reaching this part of the earth.