“When does it rain money?”/“Whenever there’s some change in the weather.”

A popular weather joke is:
 
Q: When does it rain money?
A: Whenever there’s some change in the weather.
 
“When is it likely to rain money?” was cited in print in 1940. “When does it rain money?” was cited in 1957.
 
 
Google News Archive
20 March 1940, The Age (Melbourne, Australia), “Our Junior Section—Riddles,” pg. 6, col. 4:
When is it likely to rain money?
   
Old Fulton NY Post Cards
9 December 1957, The Times Record (Troy, NY), “The Riddle Box,” pg. 4, col. 3:
When does it rain money?
Whenever there’s change in the weather.
 
Google Books
June 1959, Boys’ Life, “Think and Grin,” pg. 86, col. 1:
When does it rain money?
Whenever there’s change in the weather. — William Hertel, Melrose Park, Ill.
 
1 June 1964, San Diego (CA) Union, “Fun Time—The Riddle Box,” pg. B7, col. 2:
When does it rain money?
When there’s some change in the weather.
 
Google Books
The Abilities of Young Children
By Ruth A. Martinson and May V. Seagoe
Washington, DC: Council for Exceptional Children
1967
Pg. 25:
“When does it rain money?” Harold said. “When the weather changes.” “Very funny.”
 
Google Books
Jokes, Puns, and Riddles
By David Allen Clark
Garden City, NY: Doubleday
1968
Pg. 171:
Question: When does it rain money?
Answer: Whenever there’s some change in the weather.
   
The Hindu (India)
What’s it about money?
VINEET GILL
April 26, 2015: 
The old joke begins with a question: when does it rain money? Answer: when there’s change in the weather.
 
Twitter
Alex Willette
‏@alex_willette
When does it rain money in Las Vegas?
When there’s some change in the weather
12:11 PM - 26 Apr 2015