Instead, when the Northern Hemisphere is in winter, the Southern Hemisphere is in summer. Earth’s orbital distance does affect the overall amount of sunlight received by the planet. However, the seasonal changes in sunlight caused by axial tilt are much more important for the familiar cycle of spring, summer, autumn, and winter. When a hemisphere is angled toward the Sun, it receives more concentrated solar energy and remains illuminated for a longer duration. Conversely, when angled away, the period of daylight shortens. The summer solstice occurs when a pole has its maximum tilt toward the sun, resulting in the longest daylight period for that hemisphere. In the Northern Hemisphere, this happens around June 20-22; in the Southern Hemisphere, it’s around December 20-22. A hemisphere's winter solstice is its shortest day of the year, and its summer solstice is its longest. The equinoxes occur in March and September, and mark when the Sun is exactly above the Equator. This makes day and night equal length. As Earth orbits the Sun, this tilt changes how directly sunlight reaches each hemisphere. When a hemisphere tilts toward the Sun, it receives more direct sunlight and longer daylight. For example, in the southern hemisphere, the Sun remains in the north during winter, but can reach over the zenith to the south in midsummer. Summer days are longer than winter days, but the difference is no more than approximately two and a half hours. As Earth orbits the Sun, each hemisphere takes a turn tilting toward it. That hemisphere receives more direct sunlight and has longer days, increasing the energy it receives each day. For Southern Hemisphere residents, the sun starts staying out longer after the June solstice. Their spring equinox arrives around September 21, marking the crossover to more than 12 hours of daylight. By December, they’re at peak daylight while the Northern Hemisphere heads into its darkest stretch. In the Southern Hemisphere, June is winter and December is summer. On the date of the summer solstice, all locations in that hemisphere experience their longest days and shortest nights. January is summer in the Southern Hemisphere, and winter in the Northern Hemisphere; in July, it’s the other way around. Thus summer lasts longer in the Northern Hemisphere—giving the northern half of the globe more sunlight than the southern half over the course of the year.