Temperature, humidity and aridity:
On the coast summers are hot and very humid, with a maximum daily average of 29 C, while the mild winters have a minimum daily average of 10 C. The only areas where summers are cool in Syria, are in places with an altitude of over 1,969 feet (600 m). Slunfeh, Bludan, and Mashta al Helu are local favorites. At Aleppo, in the northwest, the average August temperature is about 30° C, and the average January temperature is about 4.4° C, and Damascus is very similar in the south. In the Desert regions of Palmyra and Deir Ezzor, in the central region at the edge of the Syrian Desert, the corresponding temperatures are about 30.8° C and about 6.4° C.
Along the West of the coastal mountainous range, Syria’s climate is very Mediterranean, however, there is a long dry season from May to September. Further inland as you approach the steppe and the Syrian Desert, the climate gradually becomes more arid, with colder and more extreme winters and hotter, drier summers.
Rain and Snow:
Summer rain is very scarce in Syria, although it appears occasionally in the extreme Northwest. Yearly rainfall in the coast and Western Mountains ranges from 762 to 1020 millimeters. Further inland as you head Eastwards rainfall decreases rapidly; the steppe between Aleppo and Damascus receives about 255 to 510 mm a year. Further towards the Desert, rainfall gradually decreases ranging from 127 mm to less than 25 mm in the southeast. Rainfall is variable from year to year, particularly in the spring and autumn months.
Snow may occur in winter away from the coast, more in high humid places and dry low lands. Frosts are common, especially in villages of high altitude locations.
In the Winter Syria is subjected to Eastern, Western and Northerly winds. The prevailing summer winds are either from the North or from the West. The Coast however, in the summer, receives winds from the West during the day, and from the East during the night. There are few sand or dust storms near the cities, however, the Desert villages are subjected to it regularly. Once or twice a year sand-bearing winds, or Khamasins, are almost 4,922 feet (1,500 m) high, this darkens the sky into a dark red color for two to three days each time.