I would bring a good shell more for rain purposes than for the cold and a good fleece or something like that to wear when you are not on the bike. Winter Jacket would definitely be overkill during the summer unless you are a "cold" person. Aside from biking gloves, it my be nice to have a pair of thin gloves or something along those lines for chilly mornings but nothing too much. Winter gloves would be overkill as well. During late August and early June, you can run into "crisp" mornings where a headband and thin gloves make the ride much more comfortable.