In the month of August the heat is generally as oppressive as in July, and often more so, although the thermometer usually stands lower. Towards the close of the month, the summer begins to break up, the wind occasionally veering from southeast, to north and northwest. Typhoons seldom occur earlier than this month or later than the end of September.
In September the monsoon is generally broken up, and northerly winds begin to blow, but with little alleviation of heat. This is the period most exposed to the description of hurricanes called typhoons, the range of which extends southward, over about one half of the Chinese sea, but not far northward; they are most severe in the gulf of Tonquin.
Northerly winds prevail throughout the month of October, occasionally veering to northeast or northwest; but the temperature of the atmosphere is neither so cold nor dry as in the following months, nor does the northerly wind blow so constantly, a few days of southerly wind frequently intervening. The winter usually sets in with three or four days of light drizzling rain.
November, and the following months, are the most pleasant in the year, at least to the feelings of persons from more northern climes. Though the thermometer is not often below forty, and seldom so low as thirty, the cold of the Chinese winter is often very severe. Ice often forms about one eighth of an inch thick; but this is usually in December or January.
The months of December and January are remarkably free from rain; the average fall, in each month, being under one inch; and the average number of rainy days being only three and a half. On the whole, the climate of Canton, but more especially of Macao, may be considered superior to that of most other places situated between the tropics.
Tables of observations on the thermometer and barometer for the year 1831. The averages at Canton are taken from the Canton Register. The averages at Macao, from a private diary, kept by Mr. Blettersnan.
| Table I. Thermometer at Canton. | Table II. Thermometer at Macao. | Table III. Barometer at Canton. | Table IV. Barometer at Macao. | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| aver. noon. | aver. night. | highest. | lowest. | aver. 7 a. m. | aver. 2 p. m. | highest. | lowest. | mean height. | highest. | lowest. | mean height. | highest. | lowest. | |||
| Jan. | 64 | 50 | 74 | 29 | 62 | 65 | 72 | 53 | 30.22 | 30.50 | 30.00 | 30.26 | 30.50 | 30.05 | ||
| Feb. | 57 | 49 | 78 | 38 | 59 | 59 | 71 | 49 | 30.13 | 30.50 | 29.60 | 30.13 | 30.40 | 29.97 | ||
| March | 72 | 60 | 82 | 44 | 66 | 69 | 77 | 55 | 30.17 | 30.50 | 29.95 | 30.20 | 30.48 | 30.05 | ||
| April | 77 | 68 | 86 | 55 | 73 | 75 | 83 | 66 | 30.03 | 30.25 | 29.85 | 30.08 | 30.27 | 29.93 | ||
| May | 78 | 72 | 88 | 64 | 77 | 78 | 85 | 71 | 29.92 | 30.10 | 29.80 | 29.95 | 30.06 | 29.85 | ||
| June | 85 | 79 | 90 | 74 | 82 | 84 | 89 | 74 | 29.88 | 30.00 | 29.75 | 29.92 | 30.00 | 29.85 | ||
| July | 88 | 81 | 94 | 79 | 84 | 88 | 92 | 81 | 29.83 | 30.00 | 29.60 | 29.87 | 30.01 | 29.60 | ||
| Aug. | 85 | 78 | 90 | 75 | 82 | 85 | 90 | 79 | 29.85 | 30.00 | 29.55 | 29.88 | 30.02 | 29.56 | ||
| Sept. | 83 | 76 | 88 | 70 | 81 | 84 | 88 | 76 | 29.91 | 30.10 | 29.70 | 29.91 | 30.05 | 29.35 | ||
| Oct. | 77 | 69 | 85 | 57 | 75 | 78 | 86 | 61 | 30.01 | 30.20 | 29.50 | 30.03 | 30.19 | 29.45 | ||
| Nov. | 67 | 57 | 80 | 40 | 65 | 68 | 80 | 57 | 30.16 | 30.55 | 29.95 | 30.14 | 30.36 | 29.95 | ||
| Dec. | 62 | 52 | 70 | 45 | 62 | 65 | 70 | 57 | 30.23 | 30.35 | 30.15 | 30.23 | 30.31 | 30.15 | ||
The average of rain is the mean of its fall at Macao, during sixteen years, furnished by Mr. Beale. The number of rainy days and continuance of winds, are the mean of four years at Canton, taken from the Canton Register.
| Table V. Hygrom. at Macao. | Table VI. Rain at Canton. | Table VII. Continuance of Winds at Canton, the mean of four years. | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| average. | high. | low. | mean quantity in inches. | mean number of rainy days. | days. | ||||||||
| N. | NE. | E. | SE. | S. | SW. | W. | NW. | ||||||
| Jan. | 76 | 95 | 46 | 0.6¾ | 3½ | 11 | 2 | 2¼ | 4 | 4 | 0½ | 0 | 7 |
| Feb. | 82 | 96 | 76 | 1.7 | 7 | 11 | 1½ | 2¼ | 5¼ | 1½ | 0¼ | 0 | 6¼ |
| March | 78 | 97 | 30 | 2.1½ | 6 | 5¾ | 1¾ | 3¾ | 10¾ | 2½ | 0 | 0½ | 3 |
| April | 81 | 95 | 50 | 5.6¾ | 10 | 6¼ | 1 | 4 | 14¾ | 1 | 0½ | 0 | 3½ |
| May | 81 | 95 | 57 | 11.8½ | 15½ | 4¾ | 2½ | 3½ | 16¼ | 1¼ | 0¼ | 0¼ | 2½ |
| June | 80 | 95 | 70 | 11.1 | 9 | 1¾ | 0¾ | 2 | 21¼ | 3 | 0¾ | 0 | 0½ |
| July | 83 | 96 | 70 | 7.7½ | 10 | 1¼ | 1 | 1¾ | 21 | 3 | 1¾ | 0¼ | 1 |
| Aug. | 84 | 97 | 70 | 9.9 | 12½ | 3 | 2 | 3 | 18 | 1¼ | 0¼ | 0½ | 3 |
| Sept. | 84 | 95 | 50 | 10.9¼ | 10 | 10⅜ | 4 | 3⅛ | 8¾ | 0 | 0 | 0 | 2¾ |
| Oct. | 75 | 95 | 20 | 5.5 | 5 | 12 | 3¼ | 3⅛ | 5⅞ | 1¾ | 0½ | 0⅛ | 5¾ |
| Nov. | 61 | 96 | 20 | 2.4½ | 3 | 23 | 0½ | 0⅜ | 1¼ | 1⅞ | 0 | 0 | 3 |
| Dec. | 71 | 90 | 30 | 0.9¾ | 3½ | 18½ | 2⅞ | 1⅛ | 2 | 2¾ | 0 | 0⅛ | 3⅝ |