Well, it depends on what kind of stuff you’re into. Skiing/snowboarding/skating is best around February. Camping or other provincial park kind of stuff is best in August or even September, when most of the bugs are gone and the parks are a little less busy.

I had the longest, most brilliant answer to this, all typed out, and then I lost it. I’ll try again later, when I’m not feeling so angry. LOL

I’ve found the best time is early fall/late summer (Late August through Mid-September). This air is crisp – the cool touch of winter is in the breeze yet it is warm enough still to be walking around in shorts and enjoying the day. If you are into skiing or other winter activities – then this is one of the Mecca’s of winter play! I think the Canadian Labor Day Holiday is the 1st of August or around there – generally that first week is jammed with local vacationers – so best to stay away during the first two weeks of August.

Really does depend on where in Ontario you’re going and what you want to do. Summer can be hell in southern Ontario, very hot and humid, but northern Ontario is nice, if a little buggy. Best time for camping and the like is usually mid August to late September for southern Ontario. Fall is gorgeous anywhere in the province, Ontario is filled with trees and the colour is amazing. If you want winter sports you might want to avoid southern Ontario until late January, winter has been a little iffy in December and January the past few years. Spring is nice, but usually fairly rainy and muddy.

It has been really beautiful the past couple of weeks, so I’ll vote for late June!