As we probably know all too well, the weather can be pretty darn strange sometimes. At the time of writing, following a cold, washout May (the fifth wettest on record), we’re suddenly plunged headlong into summer. And who can say how long that will last before the next curveball! But the weather’s got more to throw at us than we even know. From spherical balls of lighting that hover in mid-air to an optical illusion that gives you a rainbow-like halo, here are 20 of the world’s strangest weather events ever witnessed.