In the pilot, Katheryn said Toby was barely 2 when she got pregnant with Bay (actually Daphne), and she wouldn't have had time to have an affair. This means Toby would have been nearly 3 when Bay and Daphne were born, yet he was only a year ahead of them in school.
This series took place in Kansas City, but took an approach that is actually common to TV shows trying to limit their clothing and scenery budgets, which is to pretend that winters (especially fierce Midwestern winters) don't exist. Characters wear short sleeves year round.