I am about the same latitude as you.
LSU does not recommend a fall crop of sweet corn mostly because of insects.
If you want to try it I would wait at least to the first 2 weeks of Aug before I planted.
Do not expect it to be anything like the spring crop; water it well especially in the silk stage and be prepared to fight the insects.
For me it is not worth it because the corn is taking up space I could be using to grow crops more suited for fall. Such as Cauliflower; Cabbage; Brussels Sprouts; Garlic; Shallots and Onions.