High summer temperatures as mentioned is not the main limitation. My maples see highs in the 90s and 100s every summer and they are fine.
More important is that maples need a certain amount of cold to go dormant, this is an important limitation to growing them in warm climates. I cannot quote the exact requirements, you may try to find that information in the Internet.

Gomero

I'm in zone10(san diego) and have been growing few different cultivar for a few years. they do fine, just that when it gets really hot during the summer the leaves burn and they dont easily get the fall colors that is so sought after by maple grower. Some more common cultivar that are heat tolerant are: bloodgood, moonfire, waterfall.

Thanks for the answers. That's just what I needed.

I hadn't thought about dormancy too much, although it had occured to me as I read references to it and thought about the reality of winter this far south. I have not taken the time to learn about it more specifically however but it looks like I'd better do so.

Yes, you should research more closely the required dormancy period and compare that with your environment. It would be my estimate that the trees need at least two (preferably three) months of dormancy. Nightly temps of below 40 and daily temps in the low 60s would likely be sufficient, but I'm not positive on exact numbers.

Like mentioned above, high temps will not be much of a problem aside from leaf burn. Having said that I would recommend placing the tree in quite a bit of shade to ease the stress. Diseases often feed on stressed trees, and the high heat and humidity would cause stress. Here in SC, we have about 2 months of above 90 degree average temps with high humidity, and my trees do fine. However, it is the dormancy that will be the issue.

I've heard stories that disney world plants large japanese maples every few years because they have to replace them due to a lack of dormancy, but I can't confirm this.