Red Sea and its Coasts, including Somaliland.

—The horrors of the climate of the Red Sea are too well known to need comment. The whole region is almost rainless, subject to suffocating calms, and the presence of the large, but completely land-locked, sheet of water renders the relative humidity constantly high. Moreover, the whole basin is comparatively shallow, so that it becomes highly warmed even in its depths. At its southern end the temperature of the water at the surface may reach 95° F. (35° C.), and 90° F. (32·2° C.) has been registered at a depth of 5 fathoms. In the Gulf of Suez, pleasantly fresh days may be met with during winter, but in the south the mean temperature of a day seldom falls below 80° F. (26·7° C.), and in July the mean maximum temperature exceeds 108° F. (42° C.) July is the hottest month, but there is little to choose between the discomforts of any of the four months, June to September. The least hot month is January, but the climate is a singularly uniform one, the night bringing comparatively little relief, and when followed by a breeze of about the same speed as the ship, cases have occurred in which steamers have actually been obliged to put about and steam against the wind, in order to prevent the crew from falling victims to heat apoplexy.

North of lat. 19°, the prevailing winds are from the north or north-west, while in the south the predominating winds are from the south and south-east, between the two lying a belt of variable winds. From June to August north-west winds prevail over the whole Red Sea. This is known as the “Kamsin,” or fifty days’ wind, the word being derived from the Arabic root of that numeral, which, originally, intensely hot and dry, rapidly takes up moisture from the water, and is hence particularly insupportable on the Arabian side of the sea; though the fine sand with which it is loaded makes it equally objectionable from another point of view on the African side. Its velocity is often considerable, and under such circumstances may be even dangerous to the lives of those who are so unfortunate as to be exposed to its fury in the open desert. The extremely fine dust penetrates everywhere in spite of closed doors and windows, reaching even ships far out at sea. Fortunately, on the coast it is generally a good deal modified by sea-breezes springing up in the afternoon, but there is also a tendency to fall dead calm at night, under which circumstances the dark hours are even more intolerable than those of the day.

The following table of the principal climatic data of Massawa in the Italian colony of Erythrea, compiled from data contained in a pamphlet by Dr. Giovani Petella, of the Royal Italian Navy, gives a good idea of the character of the climate of the Red Sea littoral.

Massawa. Lat. 16° N.; near Sea-level.
MonthMean
Temperature		Mean
Maximum
Temperature		Mean
Minimum
Temperature		Relative
Humidity
%		RainfallNumber
of
Rainy
Days
F.C.F.C.F.C.Ins.Mm.
January78·025·690·432·468·020·075  2·0552·15·2
February78·926·092·233·468·420·276  0·6316·21·6
March81·027·294·834·970·121·274  0·6817·51·7
April84·329·098·236·872·822·669  0·112·5·2
May88·531·3101·738·776·624·766  0·5614·11·4
June92·433·5105·941·080·727·051  ———
July94·734·8108·542·584·529·256  0·133·31·3
August94·634·7106·741·583·428·557  0·265·71·7
September92·033·3103·039·478·225·760  0·174·01·0
October89·031·798·737·077·225·160  0·359·01·0
November84·329·095·235·175·023·865  0·7820·02·1
December80·727·092·033·369·520·870  2·2757·63·7

The total rainfall amounts only to 7·86 ins. (198 mm.), falling on 29·2 days in the year, but the amount and distribution is very capricious, varying greatly in different years. In so far, however, as Massawa can be said to possess a rainy season at all, the wet weather comes in the winter, instead of about August, as is normally the case in the Tropics of the Northern Hemisphere.

Sometimes a whole year may be practically rainless, as for example 1885, in which only 41·2 mm. (about 11⁄2 ins.) was collected, whereas 1891 had the respectable rainfall of 500 mm. (or 191⁄2 ins.). Apparently, however, it never rains in June.

Owing to the antiseptic powers of the intense light and heat, the place is singularly free from zymotic diseases, the cases of fever being usually not malarial, but truly climatic.

For the greater part of the year the skin is kept in a continuous bath of perspiration, and accordingly prickly heat in its most acute form, with the usual sequel of boils, is very common; as also, of course, are heatstroke and less acute forms of nervous prostration. During the continuance of the Kamsin Dr. Petella finds that the temperature of even strong and healthy individuals is raised distinctly above the normal.

The extreme character of the climate of Suakim, the frequent scene of British military activity, may be gathered from the following nearly complete table for portions of the years 1902-1903.