The Weather in Jordan
The major characteristic of the climate is the contrast between a relatively rainy season from November to April and very dry weather for the rest of the year. With hot, dry, uniform summers and cool, variable winters during which practically all of the precipitation occurs, the country has a Mediterranean-style climate.
Most of the East Bank receives less than twelve centimeters of rain a year and may be classified as a dry desert or steppe region.
The country's long summer reaches a peak during August. January is usually the coolest month. The fairly wide ranges of temperature during a twenty-four-hour period are greatest during the summer months and have a tendency to increase with higher elevation and distance from the Mediterranean seacoast. Daytime temperatures during the summer months frequently exceed 36°C and average about 32°C. In contrast, the winter months--November to April--bring moderately cool and sometimes cold weather, averaging about 13°C. Except in the rift depression, frost is fairly common during the winter, and it occasionally snows in Amman.
For a month or so before and after the summer dry season, hot, dry air from the desert, drawn by low pressure, produces strong winds from the south or southeast that sometimes reach gale force. Known in the Middle East by various names, including the khamsin, this dry, sirocco-style wind is usually accompanied by great dust clouds. Its onset is heralded by a hazy sky, a falling barometer, and a drop in relative humidity to about 10 percent. Within a few hours there may be a 10°C to 15°C rise in temperature. These windstorms ordinarily last a day or so, cause much discomfort, and destroy crops by desiccating them.