Whoa--high 80s in the day and mid 60s at night?

Beans would certainly do, or soybeans if you like edemame. Beans have the additional benefit of adding nitrogen to your soil.

If you want to get into "cover crops", buckwheat loves the warm weather.

One thing that you will want to consider is planting a second relay of cucumbers. Cucumbers fail after a few weeks--mine invariably succumb to disease carried by the cucumber beetle--I HATE the cucumber beetle most passionately.

Planting a second relay now will help keep you in cucumbers.

Plant radishes near the cukes; they tend to deter the beetles. Also dill with cukes attract the predator insects.

I would plant some sort of field peas. Either California Black eye, or my favorite pink eye purple hull field peas. They love the heat. I planted a 4X8 bed full of them. We are hitting mid 90's here. This spring has been crazy hot.

Here is a link that might be useful: My Garden Blog