Something fishy in the air? (8,3)
I believe the answer is:
mackerel sky
'something fishy' is the definition.
I can't judge whether this definition defines the answer.
'in the air?' is the wordplay.
'in the' becomes 'mackerel' (I can't justify this - if you can you should believe this answer much more).
'air?' becomes 'sky'.
'mackerel'+'sky'='MACKEREL SKY'
Can you help me to learn more?
(Other definitions for mackerel sky that I've seen before include "Pattern of small white clouds in streaks" , "Rows of small white fleecy clouds" , "high-level pattern" .)