I'll try to answer your questions in order
Lake Monona has a small group of Cats that sail as part of the Monona Sailing club on Wednesday nights and Saturday afternoons. They do have some reserved spots on the lake but you have to be a member and I don't know if there is a wait list. Most of the Cat racers live on the water and have their boats on lifts. Lake Mendota is a great lake for sailing but there a limited number of Cat’s on the water. The Mendota Yacht Club has asked CRAW to participate in a number of events this year and they are very interested in seeing CATS participate in their events.
Both Lakes have a number of boat launches but limited beach areas that you can pull the boat on.
Mosquitoes are not a problem on the water. When the are bad is usually 3 days after a lot of rain and in the grass areas. This year we have been lucky and not much at all.
Lake Monona is the most crowded lake but usually only on the weekend and if there is no wind. If there is wind the power boaters seem to disappear.
Winds are usually lighter in the summer but I have been double trapped and fully depowered in August. Just depends.
Sailing season is usually from the middle of May to middle of October. The early and late regattas can have cold weather but if you have the right gear its great sailing
Water temps for both the local lakes will be in the upper 70's to low 80's for that time of year.
There are a lot of sailors in Madison. You just need to find them and get to know them. CRAW holds 4 regattas with in 30 miles of Madison over the sailing season.
IF you need more information on Cat sailing in Wisconsin check out craw sailing.org
Capt Chaos
CRAW Secretary