Well i know what you're saying about the heat, it's 35C as we speak and its not even june yet! but i have to say as long as you start the seedlings in may at the latest and you focus on more sativa strains (as i said in a previous post) there's no bud like the one grown in heat and sun!
Yes the plants may grow a bit smaller in high temps but i can assure you they will make it just fine!!! Last year temps even reached 40s and they were fine!