July, OK
Old NL saying:  Newfoundland has 2 seasons, winter and July.
Actually fall is warmer longer than spring.  Frost may not come until late October.  My first spring there, I had snow on my 50,000 sq. ft lot on May 23.  
&, of course, it takes while for the roads maintenance crews to patch up the frost heaves.  But July can be TOOOOOOOOOO hot.
Granted I retired and crossed The Gulf in 2008.
Oh yeah, Gros Morne National Park has NS's Cape Breton Highlands National Park beat (IMHO) 1,000 to 1.
:B