Peking (lat. 39° 55′ N.) exhibits a fair average of the climate in that part of the Plain. The extremes range from 104° to zero F., but the mean annual temperature is 52.3° F., or more than 9° lower than Naples; the mean winter range is 12° below freezing, or about 18° lower than that of Paris (lat. 48° 50′), and 15° lower than Copenhagen. The rainfall seldom reaches sixteen inches in a year, most of it coming in July and August; the little snow that descends remains only two or three days on the ground, and is blown away rather than melted; no one associates white with winter, but snow is earnestly prayed for as a purifier of the air against diphtheria and fevers. The winds from the Plateau cause the barometer and thermometer to fall, but the sky is clear. In the spring, as the heat increases, the winds raise the dust and sand over the country; some of these sand-storms extend even to Shanghai, carrying millions of tons of soil from its original place. The dryness of the region has apparently increased during the last century, and constant droughts destroy the trees, which by their absence increase the desiccation now going on. Frost closes the rivers for three months, and ice is cheap. After the second crops fully start in August, the autumns become mild, and till the 10th of December are calm and genial.[25]
The climate of the Plain is generally good, but near the rivers and marshy grounds along the Grand Canal, agues and bowel complaints prevail. A resident speaks of the temperature of Nanking and the region around it: “This vast Plain being only a marsh half drained, the moisture is excessive, giving rise to many strange diseases, all of them serious, and not unfrequently mortal. The climate affects the natives from other provinces, and Europeans. I have not known one of the latter who was not sick for six months or a year after his arrival. Every one who comes here must prepare himself for a tertian or quotidian. For myself, after suffering two months from a malignant fever, I had ten attacks of a malady the Chinese here call the sand, from the skin being covered with little blackish pimples, resembling grains of dust. It is prompt and violent in its progress, and corrupts the blood so rapidly that in a few minutes it stagnates and coagulates in the veins. The best remedy the people have is to cicatrize the least fleshy parts of the body with a copper cash. The first attack I experienced rendered all my limbs insensible in two minutes, and I expected to die before I could receive extreme unction. After recovering a little, great lassitude succeeded.”[26] The monsoons form an important element in the seaside climate as far north as latitude 31°. The dry and wet seasons correspond to the north-east and south-west monsoons, assuaging the heats of summer by their cooling showers, and making the winters bracing and healthy. Above the Formosa Channel they are less regular in the summer than in winter.
CLIMATE OF THE COAST TOWNS.
The inhabitants of Shanghai suffer from rapid changes in the autumn and spring months, and pulmonary and rheumatic complaints are common. The maximum of heat is 100° F., and the minimum 24°, but ice is not common, nor does snow remain long on the ground. The average temperature of the summer is from 80° to 93° by day, and from 60° to 75° by night; the thermometer in winter ranges from 45° to 60° by day, and from 36° to 45° by night.
Owing in some degree to the hills, the extremes are rather greater at Ningpo than Shanghai. The thermometer ranges from 24° to 107° during the twelvemonth, and changes of 20° in the course of two hours are not unusual, rendering it the most unhealthy station along the coast. There is a hot and cold season of three months each at this place. The cold is very piercing when the north-east winds set in, and fires are needed, but natives content themselves with additional clothing. The large brick beds (kang) common in Chihlí are not often seen. Ice forms in pools, and is gathered to preserve fish. Snow frequently falls, but does not remain long. Occasionally it covers the hills in Chehkiang for several weeks to the depth of six inches. Fuhchau and Canton lie at the base of hills, within a hundred miles of the sea-coast, and their climates exhibit greater extremes than Amoy and Hongkong. Frost and ice are common every winter at each of the former, and fires are therefore pleasant in the house. The extremes at Fuhchau are from 38° to 95°, with an average of 56° during December and 82° for August. Along this whole coast the most refreshing monsoon makes the summers very agreeable. The climate of Amoy is delightful, but its insular position renders a residence somewhat less agreeable than on the main. Here the thermometer ranges from 40° to 96° during the year, without the rapid changes of Ningpo. The heat continues longer, though assuaged by breezes from the sea.
Meteorology at Canton and its vicinity has been carefully studied; on the whole, its climate, and especially that of Macao, may be considered more salubrious than in most other places situated between the tropics. The thermometer at Canton in July and August stands on an average at 80° to 88°, and in January and February at 50° to 60°. The highest recorded observation in 1831 was 94°, in July; and the lowest, 29° in January. Ice sometimes forms in shallow vessels a line or two in thickness, but no use is made of it. A fall of snow nearly two inches deep occurred there in February, 1835, which remained on the ground three hours. Having never seen any before, the citizens hardly knew what was its proper name, some calling it falling cotton, and every one endeavoring to preserve a little for a febrifuge. Another similar fall occurred in the winter of 1861. Fogs are common during February and March, and the heat sometimes renders them very disagreeable, it being necessary to keep up a little fire to dry the house. Most of the rain falls in May and June, but there is nothing like the rainy season at Calcutta and Manilla in July, August, and September. The regular monsoon comes from the south-west, with frequent showers to allay the heat. In the succeeding months, northerly winds commence, but from October to January the temperature is agreeable, the sky clear, and the air invigorating. Few large cities are more healthy than Canton; no epidemics nor malaria prevail, notwithstanding the fact that much of the town is built upon piles.
The climate of Macao and Hongkong has not so great a range as Canton, from their proximity to the sea. Few cities in Asia are more salutiferous than Macao, though it has been remarked that few of the natives there attain a great age. The maximum is 90°, with an average summer heat of 84°. The minimum is 50°, and average winter weather 68°, with almost uninterrupted sunshine. Fogs are not often seen here, but on the river they prevail, being frequent at Whampoa. North-easterly gales are common in the spring and autumn, and have a noticeable periodicity of three days. The vegetation does not change its general aspect during the winter, the trees cease to grow, and the grass becomes brownish; but the stimulus of the warm moisture in March soon makes a sensible difference in the appearance of the landscape, and bright green leaves rapidly replace the old. The reputed insalubrity of Hongkong, in early days, was owing to other causes than climate, and when it became a well-built and well-drained town, its unwholesomeness disappeared. The rain-fall is greater than in Macao, owing to the attraction of the high peaks. During the rainy weather the walls of houses become damp, and if newly plastered, drip with moisture.
The Chinese consider the provinces of Kwangtung, Kwangsí, and Yunnan to be the most unhealthy of the eighteen, and for this reason employ them as places of banishment for criminals from the north-eastern districts. The central portions of the country are on some accounts the most bracing, not so liable to sudden changes as the coast, nor so cold as the western and northern districts. Sz’chuen and Kweichau are cooler than Fuhkien and Chehkiang, owing to the mountains in and upon their borders.
RAIN-FALL ON CHINESE AND AMERICAN COASTS.
The marked contrast between the Chinese and American coasts in regard to rain is doubtless owing, in a great degree, to the outlying islands from Formosa to Sagalien on the former, whose high mountains arrest the clouds in their progress inland. The Kuro-siwo, being outside of them, allows a far greater mass of cold water between it and the shore on the Chinese, than is the case on the Atlantic coast, and renders it the colder of the two by nearly eight degrees of latitude, if isothermal lines alone are regarded. This mass of cold water, having less evaporation, deprives the maritime provinces of rain in diminishing supply as one goes north along the skirts of the Plain, until the Chang-peh shan are reached. The rains which fall in the western provinces and the slopes of the Bayan kara Mountains, coming up from the Indian Ocean during the south-west monsoon, fall in decreasing quantities as the clouds are driven north-east across the basins of the Yangtsz’ and Yellow rivers. In the western part of Kansuh the humidity covers the mountains with more vegetation than further east, toward the ocean. Snow falls as late as June, and frosts occur in every month of the year. The enormous elevation of the western side of China near Tibet, the absence of an expanse of water like the great lakes, and the bareness of the mountains north of the Mei ling, account for much of this difference between the United States and China; but more extended data are needed for accurate deductions.