I was there the end of March several years ago & the weather was perfect during the day in Cairo. It was chilly for the evening light show at the Pyramids.
Abu Simbel was probably my favorite site visited, but I didn't go to Petra and have kicked myself every since. I do advise adding Abu Simbel to your trip if possible, even if you have to do it on your own.

Boats moored side by side at Luxor.
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Betty