After another brutally hot summer, cooler, shorter days — and pumpkins — are on our doorstep. So is the autumnal equinox, which marks the end of astronomical summer and the first day of fall in the Northern Hemisphere. The exact time of the fall ...

On Sept. 22, the fall equinox formally heralds in autumn and marks the end of summer in the Northern Hemisphere.

During an equinox, places around the globe experience nearly equal amounts of daytime and nighttime. The second occurrence this year happens on Sunday.