Cover your tomatoes
It seems like it’s going to be a cool night tonight. The radio tells me that it might go down to five degrees tonight in Montreal. This is not a killing frost by any stretch, but it will help a lot to ripen your green tomatoes if you cover the vines while it is cold out. Tomatoes prefer weather that does not go below ten degrees.
Take your floating row cover, or a light sheet, and simply drape it over the trellis. This will trap warm air close to the tomato vines and keep them warm and happy.