Greater London is often referred to as "the City" or "the Square Mile" and it forms the main financial district. Archaically, the urbanised area of London was known as the Metropolis. In common usage, the terms "London" and "Greater London" are usually used interchangeably. Greater London is officially divided for some purposes, with varying definitions, into Inner London and Outer London. For some strategic planning purposes it is divided into five sub-regions. Greater London is under the strategic local governance of the Greater London Authority (GLA). It consists of an elected assembly, the London Assembly, and an executive head, the Mayor of
North London will report an air frost, some 119 days of the year will register at least 1mm of precipitation, and on 7.4 days a cover of snow will be observed. All annual averages refer to the observation period 1971–2000. North London North London is an informally and inexactly defined part of London, England which covers "some" of the area of the capital lying north of the River Thames. North London extends from Clerkenwell and Finsbury on the edge of the City of London financial district, to Greater London's boundary with Hertfordshire. The constituent districts were traditionally part of Middlesex with the