Xiao Wang, Xiao Li and Xiao Zhang are going to climb the mountain  The weather forecast says it may rain today  The three men argued about the weather forecast  Xiao Wang: it may rain today  That doesn't rule out the possibility that it won't rain today  Let's go climbing  Xiao Li: it may rain today, which means it's going to rain today  Let's not climb the mountain  Xiao Zhang: it may rain today, but it just shows that it is not inevitable that it will not rain today
It is up to you to decide whether to climb the mountain or not
Xiao Wang is correct, Xiao Li and Xiao Zhang are not.