CLIMATE AND RAINFALL
From what has been said about the diversity of the physical conditions
of the country it will be readily inferred that there is a considerable
variation of climate. When it is remembered, too, that the land lies
within the tropic of Capricorn and corresponds in latitude to the
central provinces of India, between Bombay and Calcutta, the reader
will be prepared to learn that it is excessively hot in the summer
months and very unhealthy. As a matter of fact the climate as a whole
is healthy and the heat much less trying than the traveller from India
expects to find in such a latitude. Various factors account for this,
as we shall see.
There are two seasons, summer and winter; summer lasts from October to
April, and winter from April to September.
The heat is sometimes great on the coast, some little distance from
the sea, where the sea mists do not reach, rising occasionally to 120°
F. in the shade. But at noon the fresh south-west wind blows strongly
from the sea, and the nights are comparatively cool and refreshing. The
sudden fall of temperature at sunset is often a source of danger to
those who have not learned to guard themselves against rapid variations
of temperature. Strangely enough, the hottest day in the year may be
a day in the middle of winter, for it is in the winter that a fierce,
hot, desert wind from the east comes sweeping across the country,
sending up the thermometer with a rush. The winter may thus have the
hottest, as well as the coldest, days of the year. A comparison of the
temperatures of the principal centres of the country with Kenhardt and
Kimberley, two of the hottest districts in the Cape Province, may not
be without interest:
-------------+---------+---------+-----
|November.|February.|July.
-------------+---------+---------+-----
Windhoek | 86 | 82 | 68
Swakopmund | 58 62 | 55
Walvis Bay | 60 | 64 | 57
Luderitzbucht| 62 | 68 | 55
Omaruru- | 82 | 82 | 62
Rehoboth | 86 | 86 | 60
Kenhardt | 74 | 85 | 57
Kimberley | 78 | 82 | 55
-------------+---------+---------+-----
The feature of the coast climate is the heavy fogs occasioned by the
proximity of the cold waters of the Benguella current to a heated
interior, and the contact of the cool south-west winds with the
north-west air currents. These fogs veil the seaboard in a thick
haze during the night and often last to noon; they supply, however,
a considerable amount of moisture to the coast border of the Namib,
since they are sometimes so heavy that in a single night the sand is
moistened to a depth of one or two inches, and the water flows down
the stems of shrubs into the ground to a depth of six inches. Heavy
rain occurs at very rare intervals. These conditions suggest that
quite a useful supply of water might be obtained by the construction
of dew-ponds, or mist-ponds, as they are now known to be, of which
particulars are given by Mr. E. A. Martin in his recent work, entitled,
“Dew-ponds: History, Observation and Experiment.” A whole year may pass
without a single shower. Walvis Bay has an annual average rainfall
of less than one inch. At such centres as Luderitzbucht, Swakopmund,
and Walvis Bay, water for drinking purposes is condensed from the sea.
Before the condensing plant was erected water had to be brought all the
way up from Cape Town.
In the north and north-east the climate is almost tropical, but on the
central plateau it is temperate, with great fluctuations of temperature
during the day. The great heat of the sun during the summer months
would make it rather trying for Europeans, were it not for the altitude
and the great dryness of the air. As we have shown, the plateau is
from 3,000 to 5,000 feet above sea level, and this is a factor of
considerable importance in determining climatic conditions. The climate
resembles parts of Rhodesia, and while there are hot days in the
summer, for the most part the air is fresh, clear, and like elixir.
Great Namaqualand has a very warm summer; the shade temperature of
the Orange River valley is often 110° F., while on the plains great
fluctuations in the day temperature prevail. In the winter severe
frosts and snow may be experienced, and snow may be seen on the Karas
Mountains. There are also occasional frosts in the Windhoek region in
this cold season.
THE RAINFALL
South-West Africa is really a continuation of the Bechuanaland plateau,
a notoriously dry territory, and the rainfall is even less than in
Bechuanaland, if we except the northern territories, since very little
of the vapour from the distant Indian Ocean can reach the country. The
Eastern slope, which faces the Indian Ocean, receives a fair supply
of moisture. The Windhoek region has an average annual rainfall of
15 inches. Whirlwinds often herald the approach of the rain. In the
warmer north and north-east 24 inches is often registered in a year.
Great Namaqualand is much drier, 6 or 7 inches being about the average.
The rain comes almost invariably in the form of violent thunderstorms
which sweep along in a limited area. It is a common experience to
travel over a stretch of dry and barren land to enter suddenly a tract
of vivid green where the vegetation is in full activity, so local
is the distribution of the rain. Severe hailstorms are sometimes
responsible for much damage, since the hailstones are often as big as
marbles. Within half an hour of the passing of one of these storms,
the thermometer has been seen to drop from 110° F. to 68° F. Droughts
of great severity continue for years together in these regions, but as
soon as the rain comes, the country revives as if by magic; grass and
flowers spring up from the steaming ground with amazing rapidity, and
the once bare and blistered plain is transformed into a vast carpet of
vivid green and brilliant hues.
The Namib has a rainfall of less than an inch, but in places where
the desert borders the inner plateau, three or four inches may be
registered during the year.
One of the journals of the Royal Meteorological Society has printed the
rainfall record of South-West Africa. Dr. Emil Ottweiler is responsible
for it, and the observations extended over periods varying from one
to twenty-three years. This record is of real value, and we give the
average fall at some of the stations mentioned.
-------------+--------------+----------
Stations. | Height above | Rainfall.
| Sea Level. |
-------------+--------------+----------
| feet. |
Luderitzbucht| 13 | 0·54
Swakopmund | 23 | 1·16
Windhoek | 5,350 | 14·07
Grootfontein | 5,020 | 24·37
Olukonda | 3,510 | 22·91
Keetmanshoop | 3,373 | 5·85
Bethanien | 3,068 | 4·52
Berseba | 3,490 | 3·11
Haris | 6,300 | 11·24
Otjimbinque | 3,084 | 5·38
Karibib | ---- | 6·01
Zesfontein | ---- | 2·73
Gibeon | 3,700 | 6·82
Rehoboth | 4,700 | 10·45
Oas | 4,500 | 18·69
Gobabis | 4,650 | 18·53
Omaruru | 3,800 | 10·85
Hatsamas | ---- | 14·06
-------------+--------------+----------
The rainfall, scanty as it is, generally descends in sharp storms and
showers, and as the ground is often baked hard by the heats of the
sun, it quickly runs away to the watercourses, but in recent years dams
have been made in order to store the precious liquid, and a well-filled
dam may hold sufficient water to supply a large farm for the space of a
year or two.
HEALTH CONDITIONS
The physical conditions already described determine the healthfulness
of the country; the sun, the elevation, the dryness, being responsible
for the good climate of the interior. The direct rays of the sun are
very strong during the day, for clouds are infrequent; many weeks may
pass without the smallest cloud being visible; but these rays are not
dangerous, and sunstroke is unusual. In India, as Bryce has shown, one
has always to be mounting guard against the sun. “He is a formidable
and ever-present enemy, and he is the more dangerous the longer you
live in the country. In South Africa it is only because he dries up the
soil so terribly that the traveller wishes to have less of him.”[4]
The extreme dryness of the air on the plateaux enables Europeans to
endure heat that would be unbearable in London or New York. A shade
temperature of 108 °F. in either of these cities would be responsible
for many a collapse, but it would pass at Windhoek without anyone being
the worse for it. Even on the Namib some compensation would be afforded
by the sea breezes.
There are people who have lived at Luderitzbucht, one of the driest
parts of the Namib, continuously for eight or ten years, and they are
exceedingly active and healthy, while at Windhoek strong and sturdy
children are developing a splendid physique in the pure, bracing air of
the plateau. Malarial fever, which hangs like a death cloud over many
parts of Africa, is sometimes found in the north and north-west of the
country, but it prevails in a mild form. Last year, for instance, there
were only six deaths from this cause among Europeans, right through
the country. The dreaded black-water fever is occasionally met with
in the tropical north. The diseases common along the coast are mostly
intestinal, due almost entirely to the lack of a good supply of pure
water. Rheumatic troubles are also fairly common on the seaboard. The
death-rate for 1913 was only 11·3 per thousand of the white population,
and 21·75 per thousand among the natives. Inflammation of the lungs,
due largely to unhealthy dwellings and lack of care with clothing,
accounts for the higher mortality among the natives.
The dryness and purity of the air away from the coast account for the
absence of most forms of chest disease. More than one sufferer from
consumption in its earliest stages, who has come from Europe, has found
a new lease of life on the salubrious uplands. There can be no doubt
that in spite of the abnormal heat sometimes experienced, South-West
Africa is well fitted to afford a pleasant home and to maintain in
vigour people drawn from the cooler regions of Europe. That healthy
children can be reared here has been already demonstrated.
FOOTNOTES:
[4] “Impressions of South Africa,” p. 13.