Possible Clues:

• Farmers look for it
• Phil Collins: "I Wish It Would ___ Down"
• Dark sky's omen
• Reason for a tarpaulin
• 69-Across source
• Water down?
• Not so fine for a ruler, by the sound of it
• "Still Falls the __": Edith Sitwell poem
• In which Sgt O'Hara intrigued Sadie Thomson
• Pavement pounder