“Snowflakes are kisses from heaven is a saying of unknown authorship that has been printed on many images. “Snowflakes, like little white kisses from heaven” was cited in the Chicago (IL) Tribune in 1882. “Snowflakes are kisses from heaven.  ~Author Unknown” was posted to the newsgroup ne.weather on March 7, 2001.
   
“Snowflakes are snow angels blowing kisses from heaven” was posted on Twitter on December 30, 2007.
   
“If kisses were snowflakes, I’d send you a blizzard” and “Snowmen fall from heaven unassembled” are related sayings.
 
   
15 April 1882, Cincinnati (OH) Enquirer “Ethelbert and Viola” (Chicago Tribune), pg. 12, col. 6:
And so in winter, when the wind was sighing with a weird cadence through the dead branches of the sturdy oaks, and the snowflakes, like little white kisses from heaven, were filling the air and noiselessly covering the graves of those who had died from drinking the Chicago water the previous summer, Ethelbert and Viola stood together in the chancel of St. Agnes/ Church, ...
     
Google Groups: ne.weather
Weather Quotes  
Joshua Lindstrom 
3/7/01
(...)
Snowflakes are kisses from heaven.  ~Author Unknown
 
Twitter
jasonarewhy
‏@jasonarewhy  
just had an original thought: snowflakes are snow angels blowing kisses from heaven. I guess there might be rain, sleet, and hail angels too
2:55 PM - 30 Dec 2007
   
11 April 2008, Des Moines (IA) Register, “Pick up the pace, April,” pg. A12:
There are all kinds of annoying quotes and sayings about weather.
(...)
“Snowflakes are kisses from heaven,” said an unknown author.
 
We say keep the kisses after March. And anyone who says something like that should remain anonymous.
     
Google Groups: alt.ads.forsale
FS: Snowflakes.snow angel kisses sign plaque - adorable (#:227140)   
AlsoShop  
11/26/08
(...)
Description of item :
Wooden block sign (hanger on back) or shelf sitter which reads snowflakes are snow angels blowing kisses from heaven.
 
Twitter
TeachHUB
‏@TeachHub  
It’s snowing!
Snowflakes are kisses from heaven.  ~Author Unknown
9:08 AM - 1 Dec 2008
 
Google Books
Spiritual Adventures in the Snow:
Skiing & Snowboarding as Renewal for Your Soul
By Marcia McFee and Karen Foster
Woodstock, VT: Skylight Paths Publishing
2009
Pg. 69:
“Snowflakes are kisses from heaven.” —Anonymous
 
YouTube
Snowflakes are kisses from Heaven 
Laura Gaia Mughetto
Published on Feb 6, 2015
 
Twitter
Agador
‏@agadorinthecity  
“Snowflakes ❄️ are supposed to be kisses 😘 from heaven but why does it keep poking my eye 👁?”… https://www.instagram.com/p/BOIiT7kjYhZ/
3:29 PM - 17 Dec 2016 from Manhattan, NY