Mobile is temperate as New York (6,5)
I believe the answer is:
empire state
'new york' is the definition.
(synonyms)
'mobile is temperate' is the wordplay.
'mobile' indicates an anagram (mobile can mean moving).
'is'+'temperate'='istemperate'
'istemperate' is an anagram of 'EMPIRE STATE'.
'as' acts as a link.
(Other definitions for empire state that I've seen before include "One nickname for New York" , "building" .)