The news was announced at a meeting of the town commissioners earlier this week.
The closure is due to take place between 29 April and 6 September.
It comes after a public survey which showed 65% of respondents supported the idea of creating an open space in the town centre.
MHK for the area, Jason Moorhouse has called it a "momentous decision" but added that local traders are concerned it could impact business.
He added: "The more we can do to make this plan work and to support local businesses, the better it will be for everyone".
Well-known farm in the west up for sale
Pet foodbank needs your help!
How much cash can government raise in 10 days, asks MHK
LegCo considers meeting on a different day
Extra promenade bus facilities would cost estimated £735k
Medieval cross returned home to Royal Chapel
Arbory MHKs in "parasite politicians" spat
Tyson Fury's boxing glove sold for £7k in charity auction