Hi Tam! Welcome to NGA.
I guess our garden-planting calendar won't help: it's based on first and last frost dates!
http://garden.org/apps/calenda...
I know that some Texas gardeners manage the heat by planting one spring crop of tomatoes (that stop setting new flowers and then die when the heat gets too bad) one one fall crop. Some people even take cuttings from their spring crop while they're healthy, and use those cuttings to start their fall crop.
I have no idea about high-heat gardening. I just barely have enough summer heat to ripen early tomatoes.