Big healthy tomato plants, but no tomatoes.

I grow tomatoes every year, I usually get a lot.

But this year, I am hardly getting anything. It is already late August, and I only have a few tiny green tomatoes.

It has been a very hot and dry summer, but I water everyday, and I thought tomatoes liked heat. The plants seem to like it.

Maybe not enough nitrogen? Would more compost help?

What usda cold hardness zone are you in? When do you start your seeds? When do you transplant your seedlings outdoors? Are you organic? What kind of tomato variety? What kind of fertilizer have you been using? Maybe your solution is simple. For one thing you are doing excellent keeping them big and healthy, now let's make them mature earlier. You've already got them flowering and fruiting too. They are just late to the party. Why is the question.

Could be lack of pollinating insects or too dry perhaps. I believe a bit of humidity is needed for the pollen to stick to the stigma, that's why the advice for greenhouse grown tomatoes in the UK is to 'damp down' paths to raise the humidity level.

My tomatoes got a poor set too, but the plants are not very well grown (low pH and poor soil nutrition...)

You probably did everything right but the WEATHER didnt.  

Very lush growth suggests plenty of nitrogen and water to me.  I would hold off adding fertility.  Do you have the same number of flowers as last year?    If you do, then the pollinators might be the issue.  Are you seeing any bumblebees anywhere in your yard?  They are the most effective pollinators for tomatoes.