Then there are the pilot reports which are hours old!
Departed (quite a busy) UK airport and the ATIS was saying "Marked temperature inversion at 500 ft..blah.blah..."
This had been reported by a departing aircraft at 0600. We departed circa 1500 and it was still on the ATIS so I reported "No temperature inversion at 500 ft etc" and then it was taken off the ATIS. I have seen the same with wind shear which had been reported hours ago but had not been taken off as nobody had reported "Ops normal".
Cry wolf too often and people stop listening as mad jock says.