'Military Report on Mesopotamia (Iraq)' [‎15r] (34/226)

17
temperature and to render it less unbearable than in
areas nearer the Persian Gulf The historical term used to describe the body of water between the Arabian Peninsula and Iran. .
In winter the winds are variable, but the general
direction is from the north-west. In summer there is a
continuous current of air from the north-west, owing to
the pressure in the Eastern Mediterranean being con
siderably higher than in the Persian Gulf The historical term used to describe the body of water between the Arabian Peninsula and Iran. during these
months. This wind, descending from the Kurdish plateau
as a dry scorching blast, is usually impregnated with
dust and, in some districts, with sulphurous fumes
distinctive of all forms of life. In the latter case it is
known as the Simoom. The relative humidity of the
atmosphere is extremely low, and even in the wet season
the rainfall is very moderate.
Within the limits of Northern Jazirah no meteorological
observations have been taken. All figures, therefore, are
approximations derived by comparing results obtained
in observation stations in Mosul and other contiguous
districts.
Rainfall .—The average monthly rainfall and number of
rain days per month are shown in the table below.
Average
monthly rainfall
in inches.
Number of
rain days per
month.
January
2 • 5(5
8-0
February
2-85
10-1
March . .
3-14
10-3
April
1-64
9-2
May
•88
5- (5
June
•08
•5
July . .
Nil.
Nil.
August . .
Nil.
Nil.
September
•28
•7
October
•37
2-8
November
1-80
6-9
December
2-32
8-2
From the above figures it is evident that during the six
months, from May to October, an unappreciable quantity
of rain falls in Northern Jazirah. During these months,
agriculture is only possible in the irrigated districts on
the banks of the Tigris, Jaghjaghah, Khabur, Balikh and
various permanent streams between the Tigris and Jabal
Sinjar. During the summer the rich grazing, which