I think cowpeas and buckwheat do well in hot weather.
I also read somewhere that people in TX plant sweet potatoes, because the vines cover the ground and shade it, even though they don't enrich the ground like legumes would. After the tubers are harvested, the vines are dug into the earth. So you get an actual summer crop, shaded ground, and biomass to dig in!
I'm in NE Florida and I like using Fava Beans, usually plant them in October/November time. I'm also going to try some Crimson clover this year and Lentils.I have Black Medic naturally growing in other parts.
Beans grow best for me at temps between 68-85 degrees. If you want beans that can take higher heat, try growing asparagus (long) beans. Beans don't like high humidity so I try to avoid growing them in the rainy season. They don't like very wet soil and they don't like their leaves to stay wet or they get fungal diseases.