I’m in Scotland, so summers tend not to be really hot - last year was the exception!
I have variations on a uniform, which are:
Midi-dress
Cropped wide-leg trousers/culottes, tucked in, fitted t-shirt
Midi-skirt, t-shirt as above
Black dungarees, striped top, or chambray shirt
I tend to wear trainers (I have loads) or brogues, but I do have Saltwaters which I actually find quite uncomfortable, and some really cheap flip-flops for knocking about at home or in the garden.
I don’t like prints other than stripes, polka dots, or leopard print - floral or ditsy prints look horrible on me. For t-shirts I like a style Warehouse do called “the smart fit t-shirt” which comes in loads of colours, plus Cos cotton t-shirts - both are about £15. I know MN hates this, but I also like a slogan tee. Midi-skirts I have from Zara, Oliver Bonas, Topshop, and Whistles, and I like Cos and Topshop for culottes/trousers. I have a dark denim jacket, and a pale oversized one, both from Topshop, which both work with pretty much everything.
I teach so am off most of the summer, and even at work am in a creative subject so don’t need to be smart-smart - I think that is much harder in summer!