I have some peonies I thought I'd put in my front porch area but it faces south and gets full sun there, I worried they could burn up?
They are just the old fashioned big full double ones that smell really strong.

Most peonies require at least 6 hours of full sun in order to really prosper. The only difference I have seen with mine is the ones in partial shade bloom and stay green a little longer than the ones in full sun.

They'll probably droop during the hottest part of summer so you'll probably have to water them regularly then but that should be the only negative. Most of mine are in full sun but I'm a zone cooler than you, I don't have any problems.

Try this if it's too sunny: position a small Fast growing tree such as vitex agnus castus in such a way as to provide afternoon shade. (I know you say southern exposure but really watch the sun this year and figure where shade falls around 1:00 in, say, July.) The vitex is a pretty little tree that won't get too tall and has neat ornamental appearance for a front yard. In your zone it might die back or be cut back to ground each winter and remains small no more than 4-5 feet. Big enough to provide shade for a peony. Plus after peony flowers are gone in mid summer vitex is covered with beautiful blue lavender flowers of its own.
Also in my zone peony foliage dies back completely and can be an eyesore in mid late summer so behind the peonies I plant lantana (perennial here, annual for you) which comes up after peonies have bloomed, the lantana needs hot days to really take off, and when it does it explodes covering the dead peonies.
Just a few ways I grow peonies in "full sun" in the South.

ok, great that helps. I was afraid the sun would burn the leaves up. I usually trimmed mine back before but I had other things planted there. So I just wondered what would happen if I tried leaving it all summer. I think I will plant them there anyway and just plant something to grow over it like you said.
I do water regular anyway so that will help.

I also grow peonies in the south, in zone 7a/7b. They're in beds with bearded irises and lilies, and they tolerate our summers fine. My plants don't go dormant until the fall.

The leaves do not burn, but the plants in full sun tend to lose their blooms sooner, due to the heat. I do have a sprinkler system, so watering them is not a problem.

I love the older scented doubles as well, I think they're just gorgeous. Be sure to provide them with support, since the stems tend to flop under the weight of the blooms, especially when it rains.

Annette

I have umrellas purchases from Crickett hills Nursery. It protects them from the sun and when it rains keeps them from getting beaten down.

I find that by planting the early bloomers, they finish blooming before it gets too hot here. I have one area where 2 peonies get the full afternoon sun and about half the time, it gets too hot and the blooms do not open properly.

Last year, we had temps up to 109 in the shade with the wind blowing. My regular peonies which were in full sun would wilt in the afternoon. I put down about 3 inches of cedar bark mulch with a strip of about a foot left open down the middle of the short bed so they would have breathing room. After soaking the bed with water a couple of times, they did not wilt. Most of the time, during hot summertime, I try to water peonies every 4 or 5 days just to give them moisture to spread and grow new roots.