The Perseids are a prolific meteor shower. They have their radiant in the constellation Perseus. The stream of debris known as Perseid cloud lies by the orbit of the comet Swift-Tuttle. The cloud are particles that are ejected by the comet as it travels on its orbit of 133 years . When Earth passes through this debris, chunks of comet-stuff burns in the atmosphere.
Perseid meteors can be spot as early as July 23 (one meteor every hour). The Perseids rapidly increase to a peak of 50-80 meteors per hour by August 12/13 and then decline to cca. 10 per hour by August 15. The last night Perseid meteors are likely to be seen this year is August 22, when is possible to see a Perseid every hour or so.
This meteor shower is visible mainly in northern hemisphere. In southern hemisphere, the Perseid radiant never climbs above the horizon. Nevertheless, during Perseid meteor shower‘s peak it is possible to see 10-15 meteors per hour coming up from the northern horizon.