People have some tricks over at troublefreepools.com

http://www.troublefreepool.com/crazy-cooling-idea-t34892.html?hilit=cooling

I can drop my pool temp by about 5 degrees by running the water features at night. That being said, it has been 100+ for a million days here in DFW Texas and my pool is right at 91 degrees, much hotter and it won't be refreshing.

Here in Florida, I am still using solar for a couple of hrs during the day. We like it at 91-92 maybe a bit warmer however we do most of our swimming at night and it really feel great even after cutting the grass in 100+ degrees. Not too bad, we are spoilt and will never go in if it less that 88 degrees. Pool temp drops to @ 88 degrees every nite.

You can add a chiller to the pool to lower the temp some