Definately too hot for tomatoes.
Good thing though because I am completely overwhelmed with them despite no blooms for 6 weeks.
Religious watering is the only reason I have any. It hasn't rained in Ladysmith basically at all since June. Brown grass and a tomato jungle is the state if my yard at present.
I like that my tomatoes bred in and for Zone 3 are doing well here too in this heat. You need to be tough and versatile to be a Canadian tomato
KarenO