The Sun appears to move northward during the northern spring, contacting the celestial equator on the March equinox. Its declination reaches a maximum equal to the angle of Earth's axial tilt (23.44°)[7][8] on the June solstice, then decreases until reaching its minimum (-23.44°) on the December solstice, when its value is the negative of the axial tilt. This variation produces the seasons.