Never rained off and on? Strange! (5)
I believe the answer is:
eerie
'strange' is the definition.
(thesaurus)
'never rained off and on?' is the wordplay.
'off and on?' indicates alternate letters (letters used at regular intervals).
'never'+'rained'='neverrained'
The alternating letters of 'neverrained' are 'EERIE'.
(Other definitions for eerie that I've seen before include "Strange and disturbing" , "Unnerving" , "Spectral" , "Spooky, macabre" , "Spooky, weird" .)