If you are visiting in the winter, don't just take shorts and T shirts - it can be quite chilly in Cairo in the early mornings and evenings, and you will certainly need to visit the Pyramids early if you want to try to get a ticket to go inside one of them. I had a light jacket when I visited and was still quite cold - heaven knows how the people wearing just T shirts managed, so make sure you have a warm jacket and long trousers.
It does warm up later in the day, so layers are a good idea.
Cairo is such a huge city and the traffic is awful, so the atmosphere is polluted. In the early morning there is frequently a thick haze covering the city, that may or may not disperse as the day progresses.
Clothes can not be worn for more than a day or two as they get grimey from the black specks in the air.
Streets are cleaned, if the orange or green overalled men with brushes is an indication, but most of the time piles of rubbish lie in the gutter, or garbage bins have been raided by cats or urchins and paper spills onto the ground.
In summer the smell of drains and sewage can be quite unpleasant
Even if you've been told that the weather is warm and that you won't get cold..beware the desert nights. It can get a bit breezy and you might be in need of a jacket to keep you warm. Just be sure that you have something extra in there ...just in case!
Although Egypt is considered a dry country, rain is not unknown. In Cairo it is not uncommon to wake up to find there has been a shower during the night.
However, sometimes there is a downpour lasting several hours. Then, the roads can be dangerous as the rain may hide the potholes, and your shoes can be ruined by the mud and puddles , as there is no drainage system to carry away the rainwater.
Cars take no notice of pedestrians and quite happily drive along side you and don't care if they splash you with muddy water or not.
The weather in Cairo is generally hot and dry almost all year round,only in winters it can be cold by night,but by day time it`s about 17C degrees.
In summers try to avoid sight-seeing by noon,it`s better to make it either early mornings or by night,tempretures can go up to 35+C degrees at noon!
It almost never rains in Cairo,in all of my visits to Cairo in the past 10 years it only rained heavely twice.
If you suffer from Asthma, make sure you carry your inhaler, the smog is very heavy, especially if you are travelling in traffic, its not good if you have any breathing problems
Keep in mind that the temperatures in Egypt could be very very high and the sun can be bloody hot. So, remember to bring suncream and sun glases….
If you have some heart diseases don't enter in the Pyramid. It is too hot and humidity is high. When we exit the pyramid, outside 50 degreases was like we entered in refrigerator.