There is no best time to travel to Egypt! As the choice of the period depends on the type of trip you want to make. For a holiday on the Red Sea, for example, the ideal period is from the end of February to the end of October, although it is preferable to avoid the strong heat of July and August.
If, on the other hand, you are interested in cultural trips and are planning to go to Luxor, Aswan, and Abu Simbel. It will be better to opt for the winter period so as to make less effort during excursions to the various tourist sites.
In general, however, August is best avoided across the country when temperatures reach annual highs. It is very advisable to travel to Egypt in Easter and Christmas and New Year 2021.