Primarily a desert type with hot dry summers (May to September) and mild winter (November to March). Rainfall occurs mainly, in the north of the peninsula and to a lesser extent in the southern mountain region.
October and April are transition periods. There are large diurnal temperature ranges, relatively little precipitation, and mostly clear skies throughout the year. The Mediterranean coast has cooler summers, higher humidity and greater cloudiness than the remainder of the peninsula.
Annual rainfall totals range from 75 to 100 mm along the Mediterranean coast to about 10 mm in the South. However, it increases to 60 mm in the mountains near St. Catherine's Monastery. The wettest period is normally December to March, with three to six rainy days a month. May to November is normally rain free, but sudden, fierce rainstorms can occur and normally dry Wadis can become raging torrents of sand and mud.
Much of the Sinai is hot, or very hot with a higher temperature inland, but there is a more temperate region near the north coast and over the mountains. During the period May/June to September/October the mean daily maximum is 28oC to 37oC in the North, 31oC to 42oC near the south coast and 35oC to 41oC inland. Minimum temperatures average between 20oC and 25oC in the summer. Humidity levels are normally highest about dawn, when between 70 and 80 percent is often exceeded.
The winter season is a little less harsh with day high's in the mid-teens and possible 20's, and evenings often falling to around 6oC - 10oC, and may drop below 0oC.