Question

first day of spring in the northern hemisphere choose first day of fall in the northern hemisphere choose december solstice solstices vernal eqinox autumnal equinox equinoxes june solstice question 2

Explanation:

The vernal equinox marks the first day of spring in the Northern Hemisphere, and the autumnal equinox marks the first day of fall in the Northern Hemisphere.

Answer:

First day of Spring in the Northern Hemisphere: Vernal Equinox
First day of Fall in the Northern Hemisphere: Autumnal Equinox