Spring Equinox 2025 Northern Hemisphere Dates. The summer solstice — is the moment when the sun, in its movement along the ecliptic, enters its northernmost point in the northern hemisphere, or the southernmost point in the southern. The spring equinox, known as the vernal equinox in the northern hemisphere, is a day on which the sun sits directly over the equator, so day and night all over the world are of equal length.

Earth’s tilt is now bringing spring and summer to the northern hemisphere. The difference between calendar and astronomical year.