You can continue to plant summer vegetables into June , though your yields will be late. Bush beans and corn produce large crops all at once a certain number of weeks after planting, so successive plantings should be done every 3 - 4 weeks. Not for them to grow, but fruit production may be inhibited temporarily by heat waves . Flowers of tomatoes, peppers, and beans will be damaged above 90 and will drop off without setting fruit, so with our typical cycle of very hot spells followed by periods with cool delta breezes, we get fruit setting every few days. Long hot spells may lead to periods later with little fruit.
Some varieties are more sensitive than others.
They grow just fine, even to 8' or more, but usually don't yield well. By contrast, 'Heat Wave' is a new tomato introduction that will set fruit even above 90. Extreme heat when corn is flowering can actually kill the pollen and prevent ears from developing. This is rare, but it did happen to gardeners in 1999 if their corn was flowering during the extreme hot spell we had in July. Slowly, deeply, and fairly infrequently.