=========+======================================= Month | STATION. +-----------+-------------+------------- | Congo, | Lower Congo | Bolobo | Mouth of | | +-----+-----+-----+-------+-----+------- | Ins.|~Mm.~| Ins.| ~Mm.~ | Ins.| ~Mm.~ ---------+-----+-----+-----+-------+-----+------- January | 3·70| ~94~| 2·93| ~74~| 5·0 | ~127~ February | 3·12| ~79~| 3·87| ~98~| 6·97| ~177~ March | 4·09|~104~| 4·73| ~120~| 4·61| ~117~ April | 3·86| ~98~| 8·87| ~225~| 7·17| ~182~ May | 2·98| ~76~| 2·84| ~72~| 5·64| ~143~ June | 0·23| ~6~| 0·19| ~5~| 0·39| ~10~ July | 0 | ~0~| 0 | ~0~| 0·04| ~1~ August | 0·08| ~2~| 0 | ~0~| 2·60| ~66~ September| 0·16| ~4~| 0 | ~0~| 3·98| ~101~ October | 0·48| ~12~| 2·17| ~55~| 6·54| ~166~ November | 3·95|~100~| 8·31| ~211~| 9·58| ~243~ December | 2·28| ~58~| 4·64| ~118~|10·80| ~260~ ---------+-----+-----+-----+-------+-----+------- Year |24·95|~633~|39·85|~1,008~|62·7 |~1,593~ =========+=====+=====+=====+=======+=====+======= _At Sierra Leone_, in spite of its lying north of the equator, the distribution of the monthly temperature resembles that of the Southern Hemisphere, the minimum falling in August, while the hot season lasts from February to May. The mean annual temperature is 77·6° F. (25·4° C.), and the average annual extreme temperatures 97·5° F. (36·4° C.) and 64·8° F. (18·2° C.). No month is absolutely rainless, and the annual rainfall is very heavy, ranging from 100 ins. (2,540 mm.) to 204·5 ins. (5,230 mm.). Curiously enough, the Cape Verd Islands are very dry, although they agree generally as to temperature with the coast, tempered by their insular position and the influence of the trade wind, having a rainfall of only about 10 ins. (260 mm.), the most rainy month being September. _Gulf of Guinea._--Along this coast there is a double rainy season; the greater from March to the end of July, and the lesser in October and November; with the dry season in August and September, and the cool Harmattan blowing between November and March. In speaking of the Harmattan as a cool breeze, it must be remembered that one refers only to the sensations produced by it; for as a matter of fact, it has no appreciable effect on the mean temperature, and feels cool only by virtue of the accelerated evaporation from the skin caused by its intense dryness. On the coast it really raises the mid-day temperatures, although it renders the mornings and evenings cooler. In the interior the Harmattan may figure indeed as a hot wind, and may be additionally disagreeable on account of the red dust it carries. 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.