In reply to Ian Hey:
Hi Ian,
It can be quite hot. I went there over Easter once and when we came back to the tent, a cork on an uncorked red wine bottle had shot out as it got so hot in the tent. Having said that, we have been there in June and it was not too bad. The main thing/problem is the thunderstorms IMHO, they are very prevalent in summer now, even spring. If you go, go really early and aim to finish by lunch. That should see you through. It's an amazing place, just not the easiest/ all quite involved.