Every three months, a new season begins—twice. 

Spring creeps in like a lion on March 1, and then again a few weeks later with the equinox. Likewise, some people welcome the arrival of summer on June 1, while others celebrate it a few weeks later with the solstice. So who is right about when the seasons begin and end?

It depends on why you’re asking. Seasons are defined in two ways: astronomical seasons, which are based on Earth’s position as it rotates around the sun, and meteorological seasons, which are based on annual temperature cycles. Both divide the year into spring, summer, fall, and winter—yet with slightly different start