..stations get their precipitation predictions correct about 85
percent of the time one day out and decline to about 73 percent seven
days out.
On the surface, that would not seem too bad. But consider that if a
meteorologist always predicted that it would never rain, they would be
right 86.3 percent of the time.
Basically, most of the time, you're better off assuming it won't rain than ever listening to a weatherman.