According to an embodiment, weather prediction apparatus divides prediction target area into grids and performs weather prediction for each grid. The apparatus includes receiver, calculator and corrector. Receiver receives observation value in each grid at a first time interval. Calculator sets first observation value received by receiver as initial value and calculates prediction value in each grid using advection model at a second time interval shorter than first time interval. When receiver receives second observation value after first observation value, corrector corrects advection model based on difference between second observation value and prediction value corresponding to observation time of second observation value.