Some serious flooding happening

The Met Office notes:

Torrential monsoon rains over the last seven days have reached life-threatening levels for communities south of the Himalayas from Nepal to Bhutan and northern India to Bangladesh.

Severe floods and landslides have wrought havoc. Already across the affected region communities have faced tragedy, including: loss of life; thousands of homes submerged; extensive crop damage; as well as collapsed bridges and blocked roads.

Further heavy rain is forecast over the next few days and this will extend the zone of flooding downstream to communities lining those major rivers which flow from the Himalayas.

As for whether the amount of rain is unusual - yes, it surely is, in some parts:

The monsoon is a natural part of south Asia’s weather, but this year rainfall in some areas has been over four times greater, when compared with the average between 1981–2010.