The conditions were almost ideal for observing the Perseids in 2021. Peak activity was expected between 3 and 6 p.m. (Eastern) on August 12—late afternoon for observers in Eastern North America. However, remaining uncertainties in the exact moment Earth comes closest to the densest parts of the meteor stream mean this window could in fact extend from 10 a.m. to 11 p.m.
For observers in Eastern Canada, the nights of August 11-12 and 12-13 were equally good for observing the Perseids.
A crescent Moon favorable to observation
In 2021, the Perseids reached their peak activity when the moon was just a thin crescent (new moon was on August 8, first quarter occured on the 15th), and it sets before 10:30 p.m. This means the sky has been moon-free during the second half of the night: that’s when the radiant of the Perseids, located in the constellation Perseus, climbed higher in the sky, thereby increasing the number of visible meteors—until the encroaching light of dawn puts an end to the show.
During the two nights closest to peak activity, up to 50 Perseids per hour could be counted under clear, dark skies, free from light pollution.