Your Specialist will be able to tell you more about the region’s climate, including details of regional festivals, but here is a general guide.
Most visitors arrive in Egypt between October and April, when Cairo and Lower Egypt are pleasant and Upper Egypt (around Aswan and Luxor) a few degrees warmer but still pleasant. The summer season, from May to September, is exceptionally hot but the high temperatures are alleviated by dry air, low prices, air-conditioning and far fewer visitors.
Moroccan temperatures vary considerably over the course of a day, and a sweater may be necessary even on a summer evening. The coastal regions see pleasantly mild winters and warm summers, the southern desert areas reach an average of up to 40º Celsius in summer, and the high interior can be visited year-round, although it gets cold enough in winter for snowy peaks.
Libya and Tunisia’s weather can be variable, influenced by the Sahara Desert and the moderating influence of the Mediterranean Sea, but high summer tends to be too hot for most people. The Sahara is of course hot in summer but nicely cool in the winter.
Jordan has a typically Middle Eastern climate, with very hot summer days. However, it is worth considering a trip at this time as you will have sights like Petra almost to yourself. Spring and autumn are the best times to travel, as the days are warm and nights cool. Winters can be surprisingly cold, and Petra has sometimes experienced snow. Desert nights can be decidedly chilly but gloriously clear.
Oman is not a summer destination, as both temperatures and humidity are unpleasantly high. However, from October through to April days will rarely if ever be anything other than lovely. Temperatures are considerably cooler in the mountains than on the coast. Salalah actually has a monsoon season, called the khareef - from June to September, wet winds create a thick fog that coats the mountains, creating luxuriant green hills.