“Never catch snowflakes with your tongue until all the birds have gone south for the winter” is a winter holiday tip that has been printed on many images. That is, the white stuff falling from the sky might be bird droppings instead of snow.
     
“Never catch snowflakes with your tongue until all the birds have flown south for the winter” was posted on the newsgroup alt.pets.parrots.cockatiels on December 5, 2002. “What’s a good Christmas tip? Never catch snowflakes with your tongue until all the birds have gone south for the winter” was printed in the book Blonde Walks into a Bar: The 4,000 Most Hilarious, Gut-Busting Gags, One-liners and Jokes (2008) by Jonathan Swan.
   
           
Google Groups: alt.pets.parrots.cockatiels 
strange angry pecking behavior
Gordon Lee
Dec 5, 2002, 9:41:29 PM
(...)
Gordon Lee
Great Fritain Royal Memorabilia & Fickled Feathers Emporium
Never catch snowflakes with your tongue until all the birds have flown south for the winter.
 
Google Groups: alt.humor.puns
Puns of the Weak 12-13-04
Stan Kegel
Dec 14, 2004, 1:39:49 PM
(...)
Never catch snowflakes with your tongue until all the birds have gone south for the winter. (Cookie)
 
Newspapers.com
18 December 2005, Battle Creek (MI) Enquirer, pg. 1B, col. 2:
Want a good holiday tip? Never catch them with your tongue until all the birds have flown south for the winter.
 
Twitter
Wout Keunen
@woutkeunen
Never catch snowflakes with your tongue until all the birds have gone south for the winter
3:09 PM · Dec 13, 2007·Twitter Web Client
     
Google Books
Blonde Walks into a Bar:
The 4,000 Most Hilarious, Gut-Busting Gags, One-liners and Jokes
By Jonathan Swan
Berkeley, CA: Ulysses Press
2008
Pg. ?:
What’s a good Christmas tip?
Never catch snowflakes with your tongue until all the birds have gone south for the winter.
 
Twitter
TeachHUB
@TeachHub
Q: What’s a good holiday tip?
A: Never catch snowflakes with your tongue until all the birds have gone south for the winter.
2:17 PM · Dec 11, 2008·Twitter Web Client
     
Google Books
The Mind Is a Funny Thing
By JayMat Hornetoad
Marianna, FL: International Mobile Publishing
2010
Pg. 53:
What’s a good holiday tip?
Never catch snowflakes with your tongue until all the birds have gone south for the winter.
 
Twitter
Gary Love
@thecloverloves
Grandma said:  “Never catch snowflakes with your tongue until all the birds have gone south for the winter.”
4:05 AM · Dec 15, 2015·Twitter Web Client
   
Twitter
Nancy Herberholz
@nanron5350
Q: What’s a good holiday tip?
A: Never catch snowflakes with your tongue until all the birds have gone south for the winter.
9:21 PM · Dec 16, 2015·Facebook
 
Twitter
Lorraine Jo King
@lahlahbean
#mondaymirth #Christmas
What’s a good Christmas tip?
Never catch snowflakes with your tongue until all the birds have gone south for the winter.
3:00 AM · Dec 21, 2020·Twitter for iPhone