Just as above really :)
That is our itinery, spending 6ish days on the banks of the Ardeche. Weather stats suggest that top temps could be 29-30 degrees
However...... Our tent has never seen such temperatures indeed it could well collapse in the mere presence of sunshine so inhale no idea how stuffy it could get. We have a sewn in groundsheet, which I believe that many tents sold to that area don't, to allow free movement of air.
Will it be unbearable? We are all sun lovers, including the two dogs. I'm just slightly concerned though that such heat could get oppressive and in a tent we will have no escape. Our next port of call is likely the Jura which appears to be slightly cooler. If it really will be hard work we may skip the Ardeche for another time :(