At September 7 2016 Microsoft made available Azure and Office 365 in two UK regions.
The map below shows the UK West (Cardiff) and UK South (London) regions. Microsoft is working on two Germany based Azure datacenters. These will be isolated from worldwide Azure.
Most of the services and virtual machine sizes are available in the UK regions. For an overview see this table.
Azure is general available in 28 regions around the world. In total over 100 datacenters are in use delivering Azure services to customers.