each year i fish mississippi river pool 4 in the winter, and the walleye run up on rainy river is cold but the fishing is amazing... typically there is water temps from 33-40 depending on the year...

 

mitch

not frozen i fish.. got one of my biggest bass last year slow rolling a swimbait after its snowed

I fish whenever the water is soft. Generally, I don't see surface water temps colder than 35 degrees however.  The coldest surface water temp where I've actually caught a bass was 38.  This is from the bank.

 

Surface water temp was about 37/38 when this shot was taken in January...

 

u are 1 crazy dude

35 was the coldest I've seen

If the water is not frozen I am fishing. I will be fishing the first weekend day that the ice is gone (hopefully this coming weekend).

From shore I fish as long as the water is not frozen.  However, myself and two friends have been known to launch the boat in ice and slow motor to our area.  Once there, we make a straight, slow run to break the ice, then turn the boat and go back through the same area, only this time with the bow riding high so we throw as big a wake as possible.  We do this a few times, then give things about 10 minutes to settle down and commence fishing.  It surprises people how many fish we have caught with this method.  Of course, it really only works well with ice less than 1".