It was around 100 when I was there a month ago. Outside there's plenty of shade and water misters in a couple if area's that I remember. Inside the castle are some large but quiet fans. My aunt (aged 72) and myself (aged 57) were fine. Just take bottled water with you and enjoy the tour.
Hotter up at the castle than down below. No AC in the castle.
Thanks! Your answer is awaiting moderation.