Seems now is indeed the time for the garden spiders, the Argiope! They're likely getting ready for the winter, laying egg sacs so that new spiders will be ready when summer comes again. This one a beautiful female. The yellow is to help them not getting eaten by birds (because they're so large, they make a tasty snack to birds), but these spiders are not medically significant to humans. They hardly bite, and would rather just run away. She won't mind if you throw a moth or small cricket into her web every now and then. Thanks for sharing your spider!