Anna
Think in terms of microclimates - I have to believe your house is airconditioned? I would think the a/c would keep your house cooler in the summer - just as in my location, the heat from my house in the winter tends to keep things warmer. I would think this would work in reverse - also try the northern side of your house as that should be cooler than the southern side....
Let us know how it goes - I am wondering as well...
