The rainfall is everywhere very heavy, that of the Cameroon district reaching the enormous figure of 350 ins. (8,970 mm.), the second greatest in the world.
The mean annual temperature is about 77° F. (25° C.), with annual extremes of 89·6° F. (32° C.) and 68° F. (20° C).
The following table of the climatic data for the coast of British Nigeria will give a fair idea of the conditions that will be met with in the coast towns of the group of colonies in this region:—
| Old Calabar. Lat. 4° 58′ N.; Long. 8° 17′ E. | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Month | Mean Monthly Temperature | Mean Monthly Maxima | Mean Monthly Minima | Relative Humidity Per cent. | Rainfall | Number of Rainy Days | ||||
| F. | C. | F. | C. | F. | C. | Ins. | Mm. | |||
| January | 83·4 | 28·6 | 90 | 32·2 | 68 | 20·0 | 78·8 | 2·68 | 68·1 | 1 |
| February | 86·5 | 30·3 | 94 | 34·4 | 72 | 22·2 | 78·1 | 6·69 | 170·0 | 5 |
| March | 84·8 | 29·2 | 94 | 34·4 | 71 | 21·7 | 81·6 | 7·70 | 195·6 | 8 |
| April | 85·5 | 29·7 | 93 | 33·9 | 71 | 21·7 | 75·8 | 11·01 | 279·5 | 10 |
| May | 81·9 | 27·8 | 94 | 34·4 | 75 | 23·9 | 77·6 | 10·95 | 279·0 | 19 |
| June | 80·8 | 27·0 | 92 | 33·3 | 71 | 21·7 | 84·4 | 32·59 | 827·0 | 22 |
| July | 77·9 | 25·5 | 90 | 32·2 | 70 | 21·1 | 85·8 | 13·61 | 345·4 | 25 |
| August | 77·1 | 25·0 | 86 | 30·0 | 70 | 21·1 | 88·2 | 6·39 | 162·4 | 15 |
| September | 80·8 | 27·0 | 92 | 33·3 | 70 | 21·1 | 85·7 | 11·84 | 300·0 | 25 |
| October | 82·3 | 28·0 | 91 | 32·8 | 70 | 21·1 | 83·6 | 9·38 | 238·0 | 17 |
| November | 82·3 | 28·0 | 91 | 32·8 | 71 | 21·7 | 83·9 | 11·34 | 288·3 | 12 |
| December | 81·9 | 27·8 | 89 | 31·7 | 70 | 21·1 | 83·6 | 1·32 | 33·6 | 1 |
| Year | 82·2 | 28·0 | 94 | 34·4 | 68 | 20·0 | 82·1 | 119·50 | 303·6 | 150 |
The remarkable uniformity of the temperature data is very striking. In the interior of Nigeria, however, much higher temperatures are experienced, especially at the times when the hot Harmattan is blowing off the northern deserts, the noon temperature at such times being rarely under 100° F. (37·8° C).
As we get farther south the temperature moderates and the rainfall rapidly diminishes; the mean temperature in Angola being no more than 68° F. (20° C.), while in the elevated interior the climate is neither disagreeable nor unhealthy.
Dr. Yale Massey sends me the following information from his Mission station in the Benguela district, at 4,700 feet, lat. circa 12° S.; and long. 17° E. “The distinctly wet months are from October to April inclusive, and this is also the hot season. There are usually a few showers in September, and rarely some in May, and during the dry season there is usually a strong breeze. In the wet season the mid-day temperature ranges from 80° to 100° F., at night from 45° to 60° F.; while during the dry weather the mid-day temperature is from 70° to 90° F., and at night even slight frost may occur. As might be expected from the elevation and climate, this is a generally healthy locality, but there is a certain amount of fever, most of the cases occurring in April and May.”
East Coast.
—The reputation borne by the east coast is scarcely more enviable than that of the western, the accounts of travellers voyaging on the Zambesi being generally alternate wails on attacks of mosquitoes and upsets from hippopotami. The rainfall is, however, much lighter, and at corresponding latitudes the temperatures generally seem somewhat lower.
Owing to the presence of a considerable Arab element, the population have attained, in some places, a larger grade of civilisation than is the case on the west coast, so that the introduction of hygienic measures might be somewhat more practicable, albeit that Arab civilisation, per se, has hardly reached the stage of promoting sanitation.