One reason why there is winter in Egypt, since Egypt is considered a "desert".
Note: A "climate" type can be defined by the amount of precipitation received (characteristic of weather) over long term periods (climate).
Arguably, this makes a case for "amount of precipitation" a poor "defining characteristic" of climate. For instance, Antarctica is considered a "desert" / yet is very different from the "Mojave Desert" in California (U.S.A.), for instance.
In particular, Egypt only has two seasons (mild winters and warm summers) due to its proximity to the Equator and due to its lack of mountains.