“Summer is two weeks of bad sledding” is how the summer season is jocularly described in some cold places, such as Buffalo (NY) and Canada. For slightly warmer regions, summer can be “four weeks of bad sledding” or “eight weeks of bad sledding.”
 
“We (Canada—ed.) are with only about two weeks of bad sledding a year, in July” was cited in The Globe and Mail (Toronto, ON) in 1970.
 
   
16 February 1970, The Globe and Mail (Toronto, ON), “By Dick Beddoes,” pg. 18, col. 1:
Perhaps the first law of life in Canada is that we are a winter-sport nation, burdened as we are with only about two weeks of bad sledding a year, in July.
 
2 March 1986, Playground Daily News (Fort Walton Beach, FL),  “Looking for a new nest” by Jim MacKinnon, pg. 5A, col. 1:
Once upon a time, in the most northern regions of the continent, there lived a flock of hardy birds who thrived and survived in a harsh climate of bitter cold winters and summers that were referred to in jest as “two weeks of bad sledding.”
   
Google Groups: rec.gardens
Zoysia Grasses
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6/4/92
(...)
It’s a warm-season grass, and in your neck of the woods, where summer is two weeks of bad sledding,
 
Google News Archive
31 August 1997, Sunday Star-News (Wilmington, NC), “N.C. State perspective is changing with victory” by Mike Boaz, pg. 8C, col. 1:
The boot’s gone, the sun’s shining, even in Syracuse, where summer is just two weeks of bad sledding anyway.
 
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Duncan Phyfe
‏@duncisms
@AliveinMe well our summer is defined by “2 weeks of bad sledding”
4:29 PM - 30 Sep 2009
 
Twitter
Matt Forbeck
‏@mforbeck
@jefftidball Yeah, but you’re in northern Minnesota. Summer there is three weeks of bad sledding.
2:01 PM - 1 Oct 2009
 
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Harold Boughton
‏@HaroldBoughton
@PatMcAfeeShow @WTHRcom In Buffalo, we used to describe Summer as two weeks of bad sledding! But, I do love Buffalo!
6:04 AM - 22 Apr 2015