Egypt is known for its pleasant climate.
Climate is effectively a natural factor in man’s life
and his development.
It is known for its dry weather, which was an important element in ancient Egypt,
and still is for those who want to escape the cold and rainy countries.
For those who can cope with heat better than with cold
traveling to Sinai in summer time is still recommendable
This is especially true because there is hardly humidity to be expected.
Besides, there are less tourists in that time, so that more individualism is secured.
Despite warm and sunny weather throughout the whole year,
in some part of the desert it might become coldy in winter times.
In higher areas it might even snow (e.g. St. Catherine), but only in the months of December to February.
Considering this, people that are visiting colder areas should bring warm clothes as well.
General:
Sinai’s weather is easy to summarize: it is sunny and dry with a clearer sky.
Right travel time:
From March to May as well as from September till November
are probably the most pleasant times for traveling.
Especially in spring time there is more vegetation
and and water will be found in the oasises.
In winter (December-February) it does become colder,
but usually it is still enough for swimming