Qualification of Cold Storage facility

Dear All,
Hope you all are doing well.
If the user requirement is to maintain the area at 2 to8 C then in that case what’s an acceptable limit in terms of MKT and average temperature.

Please refer WHO Guidelines on Qualification of Temperature controlled storage areas- Technical supplement to WHO Technical Report Series, No. 961, 2011, January 2014, Annex 9: Model guidance for the storage and transport of time and temperature–sensitive pharmaceutical products.