Having more showers is way to control foul air rising (7)
I believe the answer is:
rainier
'having more showers' is the definition.
I can't tell whether this definition defines the answer.
'way to control foul air rising' is the wordplay.
'way' becomes 'R' (abbreviation for right).
'to control' becomes 'rein' ('rein' can be a synonym of 'control').
'foul air' becomes 'ia' (I can't explain this - if you can you should believe this answer much more).
'rising' says the letters should be written in reverse (in a down clue, letters go up).
'rein'+'ia'='reinia'
'reinia' reversed gives 'ainier'.
'r'+'ainier'='RAINIER'
'is' is the link.
Can you help me to learn more?
(Other definitions for rainier that I've seen before include "More wet - Monaco's late prince" , "Mountain" , "Prince of Monaco, married to Grace Kelly, d. 2005" , "weather getting worse" , "This is more likely to pour down" .)