Since we are driving from Wisconsin to Fort Sill Oklahoma May 9th, for our kids Basic graduation, I was thinking about making a stop on the way back to the Lake of the Ozarks with our boat. Is it safe to say the water temperatures are probably still pretty darn cold? Would anything really be going on that early in the season?

To get a good answer on this you need to post this on the MidwestBoatParty site. Almost all of the LOTO guys are on that site.

I would say that the water is going to be around 50 to 60 degrees at most that time of year. If you want to get out and run the lake it would most likely be pretty quiet and a good time to do that. I also suspect that most of the on the water bars would be open.

As for the water temp that's kind of what I expected. Thanks for the response.

Month late on this thread but.......

You might consider moving your LOTO plans to the week before if possible.
Harbor Hop is May 4th which is generally regarded as the "opening" of the season.
Also a big car show at the dam.
http://funlake.com/harborhop/
http://www.mikefinksmarina.net/Upcoming_Events.html

Unless you are planning to boat Grand too (doubt there is anything going on), I would look at storing the boat instead of dragging it the extra distance.
I have used the Boat Yard a couple times I have laid my boat over for two weeks. They charged a $30 min which is good for a month of gated outside storage.
573-348-0940

Water will be cool, especially this year but boats should be out and most places open.