Here are links to events in the Houston area that *usually* take place in September. We’ve tried to provide the most direct link to information about the event. However, you may have to click around a bit depending on the site.
Bayou Bend Family Days ~ third Sunday of the month, September through May
Garden Faire & Fall Festival at Mercer Arboretum
Children’s Museum of Houston Homeschool Day (sometimes at the beginning of October)
Hummingbird Festival at Kleb Woods
Miller Outdoor Theatre Children’s Performances ~ various weekdays April through September.
Smithsonian Magazine Museum Day Live! ~ Beginning in May, pre-register and print your free admission to participating local museums for a chosen date in September.