theskull once bubbled...
We have year-round diving in the Illinois/Missouri area. Our lakes and quarries typically get better visibility when the water gets colder, and the sites are not crowded with the less dedicated divers. And then there are the caves. . . 55-60 F year-round.
Lake & quarry temps vary between 70 F to an occasional 90 F in late summer.
Spring/Fall varies between 42 to 76 F.
Winter varies between 34 to 42 F.
All you need is a dry suit, a couple buddies who love the water, and an environmentally sealed regulator. And of course a cooler full of hot water for the hoods and gloves.
theskull