A question I often see, especially from Americans, is why the March Equinox is much colder than the September Equinox -

https://imgur.com/gallery/XrOef6e


I would leave this as an open question to answer were it not for nuisances who exert no discipline in this newsgroup by attempting to muddy what is fairly straightforward and much like everything else.


The reason the March Equinox is colder than its opposite in the Northern hemisphere relates to the fact that it is Polar sunrise today at the North pole while Polar sunset happens at the South pole. Much like sunrise is almost always colder than sunset during the 24 hour day/night cycle then likewise the same applies to orbital sunrise in the Northern hemisphere and best appreciated in isolation at the North pole.

So today is the astronomical event of two distinct types of sunrises and sunsets arising from two distinct surface rotations of the planet.