Landslides tend to occur after torrential downpours or earthquakes.  There are some that are painfully slow in developing, but have the same devastating effect.  Geologists have a hard time figuring out the timing and location of slides, but the general rule of thumb is that the risk of landslides increase during wet cycles. Insurance policies routinely omit landslides because they can be so hard to detect.  When it comes to landslides, never ignore an evacuation order.