Hopefully someone with more direct knowledge of grocery store produce can chime in, but two things to pull from the link below as far as Ontario crops:
- crops come twice a year, once in summer and once in fall
- the Spotted Wing Drosophila fruit fly wreaked havoc on the summer crop in Ontario at least, to the point of wiping out some entire harvests for some growers:
http://www.cbc.ca/news/canada/london/raspberries-spotted-wing-drosophila-london-1.4216152
Maybe someone more plugged in with a grocery store can comment on when fall crops would normally come in, how supply and pricing are this year and when raspberries shift to coming from other sources like California (keeping in mind that Ontario is far from the only area with SWD problems). You could also chat with someone in the produce section of your grocery store... I know last year when I was looking for a lot of oranges for juicing they had offered to do a custom order for me. If you go that route, please keep us posted on what you find out!