How about heading out to sea this September?
I recently started listening to Patrick O'Brian's Jack Aubrey & Stephen Maturin series during my commute. If you haven't read these books and you're looking for a impecibly researched adventure on the high seas, then this series is for you. If you have read them and you're pining for the open sea, intrigue, and the roar of broadsides, consider listening to them.
The first two, Master and Commander and Post Captian are read by one of my favorite narrators, John Lee, who also narrated Pillars of the Earth and World Without End--two more (and very different) excellent historical narratives.
Get hooked on this 21-book series and it may just last you through the winter!