Interview outfit in hot weather

[Birdy65]

Hi
I have not had an interview for a number of years and I have one in two weeks time. What can I wear if the weather remains hot? I do not usually need to wear suits or formal dress for week but this interview is for a Manager’s position so I will need to buy something.
I don’t think I can go without tights, but I know I can get the barely there ones from M&S.
I have some navy Boden 7/8 Richmond trousers, though as I’m an apple shape Amd a size 14 I need to avoid any blouses tucked in. Any ideas?

What do you think of this?
www.thewhitecompany.com/uk/Pleat-Sleeve-Dress/p/PDCAT?swatch=Navy

I have a similar dress in black from the White company, though it is in a heavier material (acetate 80% and polyester). It is unlined though but just wondering whether black would look too harsh in the summer? Also, would I need to wear a blazer/jacket? What colour with navy and black?

www.next.co.uk/g52327s4#614862