'Handbook of Yemen' [‎9r] (22/190)

fairly cool by night, but it is comparatively free from the
enervating dampness of the coastline. The rainfall is
scanty and irregular.
The Maritime Range and Intramontane Uplands have
a feverish climate with close, muggy nights,_ especially in
the rainy season among the foothills ; but in proportion
as the elevation increases, the air becomes more healthy
and bracing. The chief rainfall occurs in _ spring; but,
on the higher ground, there is some precipitation in summer
as well, chiefly in thunderstorms.
On the Mam Ridge, at 5,000 feet elevation and above,
winter fogs are prevalent. The mists come up from the
ravines in the earlv afternoon, and lie thick till next
morning and sometimes all next day. They are not,
however, without their advantage, as they favour the
growth and development of the coffee plant. This zone,
with its regular rainfall, due to the influence chiefly of the
south-west monsoon, may be considered the most favoured
district of Arabia. It has indeed two rainy seasons, one
in early spring and another in late summer with the
north-west monsoon.
The inland Plateau has a much drier climate, of which
that of San'a may be taken as fairly typical. Here it is
cool and pleasant all the year round ; the nights are cold
in winter, but the' days warm, and in the summer the heat,
though considerable, is not oppressive, owing to the dryness
of the air, a difference of more than 20° being sometimes
observed between the wet and dry bulb thermometer
readings in May. It is not, however, necessarily a healthy
climate, high altitude in tropical countries involving anaemia
and other peculiar disadvantages. The eastern slope,
however, has much smaller and less certain rainfall than
the west. The bulk of it is expected in summer, but the
wet periods are often short, and local droughts are not
uncommon.