Temperature reflects most of Gary, Indiana - to begin with, it's cold and dreadful (6)
I believe the answer is:
tragic
'dreadful' is the definition.
(thesaurus)
'temperature reflects most of gary indiana to begin with it's cold' is the wordplay.
'temperature' becomes 't' (abbreviation).
'reflects' shows that the letters should be reversed in order.
'most of' means to remove the last letter.
'to begin with' suggests taking the first letters.
'it's cold' becomes 'c' (eg on taps).
The initial letter of 'indiana' is 'i'.
'gary' with its final letter removed is 'gar'.
'gar' back-to-front is 'rag'.
't'+'rag'+'i'+'c'='TRAGIC'
'and' is the link.
(Other definitions for tragic that I've seen before include "Calamitous, very sad" , "Pitiable" , "Awful" , "Greatly distressing" , "Disastrous, appalling" .)