First, the odds are roughly one in ten or twenty that a given earthquake will be followed by a larger earthquake, with most of the risk in the first days. On thin data, this rule of thumb is thought to apply to a wide range of magnitudes - most think earthquake behavior is fairly self-similar (also called scale-invariant, which is one kind of fractal behavior). So the relation applies equally to M2 and M6 events.

Second, most seismologists don't believe there is any particular weather that tends to coincide with earthquakes. The earthquakes strike miles underground, under pressures of many thousands of pounds per square inch, and conditions down there are not much influenced by the air up here.

I don't have the lists and counts of earthquakes handy.