You Do Need power plug adapter while traveling from United Kingdom (UK) to Niger.

Here is Why You Need An Adapter

The outlet and plug type used in Niger are C, D, E and F and in United Kingdom (UK) is G. This is how they look like.

United Kingdom (UK)

In United Kingdom (UK), outlets of type G are in use.

Type G

Niger

In Niger, outlets of type C, D, E and F are in use.

Type C

Type D

Type E

Type F