Having been there in the middle of August I'd suggest a cool linen shirt.

Make sure her shoulders are covered. I wore some 3/4 length linen trousers and a linen shirt.

At the risk of sounding like an old lady - comfortable shoes!

... and someone recommended to me to wear full shoes rather than flip flop types as the sand is so hot it burns your feet !

my husband wore three quarter lenght trousers and a t-shirt and i wore three quarter lenght trousers and a thin top but it covered my arms and shoulders, dont want to offend their culture

at this time of year cotten shirt and long light weight trousers for men and probably the same for women . you would be better in shorts but that would draw attention to you .,which could be unwanted

Hi
I live in Cairo so will be able to help

Cairo is not as free as the red sea resorts, shorts are frowned upon although we do see them but in order not to offend don't wear them.
No spaghetti tops but you can wear a sleeveless tshirt for when you are inside but bring along a cotton shirt to cover your arms when you are outside.
Comfortable shoes/sandals
Loose cotton type trousers are the most comfortable, it is too hot for jeans in the summers months.
If you are going to the Pyramids.. bring a sunhat it can be intense out there.
If visiting the museum be aware this is expensive as the entry fee is just that, to go into the mummy room is extra but to see King Tuts death mask is free. You cannot take photographs inside the museum.
Khan Khali .. the souk is expensive and you can usually find the items on sale around the city at a smaller cost.

why is the citadel never mentioned to tourists . it is a good inexpesive way to pass a few hours .

My husband and I both wore t shirts and three quarter length trousers. Don't forget your hats

If you are having a day trip to Cairo you are probably on an organised tour and that is why you probably don't get to the Citadel.
Traffic being the way it is in the city.. going to the museum and then out to the pyramids has taken up most of the day.
One thing I cannot understand and I see daily as I live on the corniche Why do tour companies take tourists to TGI Fridays for lunch? Personally I would not go and would tell them I want to eat in an Egyptian Restaurant.

Scottishmaiden, we have just returned from Egypt and went on an organised tour with Thomson - the Citadel was the first place we stopped, before going on to the pyramids and then the museum.

hi were just back on thursday, i wore three quarter lenghts n a tshirt same as last year and all was fine