Astronomers say the spectacle occurs when the earth slams into material shed from the comet 109P/Swift-Tuttle as the planet moves around the sun.
That is what makes the occurrence so spectacular - it's like watching the mechanics of the solar system at work.
They are best viewed in the northern hemisphere; below is a picture of last night's view in Clydebank, West Dumbartonshire.
Perseus rises in the north-east as the sun's going down so you want to look maybe more over towards the east.
It is also advisable to look at them out of the corner of your eye as peripheral vision is more sensitive under low-light conditions than central vision.
Dr Ed Bloomer, a senior astronomer at the Royal Observatory Greenwich, says there would not be a dramatic rise in visibility between last night and tonight.
He told The Guardian: "The Perseids should give good viewing a couple of days either side, with local weather and light conditions probably more significant factors than the precise mathematical peak."