HKG-CAR1920-1930 — Page 58

1920-1930

HONGKONG, 1921.

(c)-CLIMATE.

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The principal features of the weather in 1921 were :—

(a) Heavy rainfall from April 27th to July 6th, during which period 59 inches of rain fell on 59 days; and a drought from September 9th to the end of the year, when only 1 inch of rain fell.

(b) Abnormally low wind velocity in March, increasing gradually to normal in July.

Barometric pressure was considerably above normal in January, July and October, and considerably below in May, June and August. The mean pressure for the year at station level was 29.848 ins., as against 29.814 ins. in 1920 and 29.843 ins. for the past 38 years. The highest pressure was 30.323 ins. on January 14th, as against 30.374 ins. in 1920 and 30.509 ins. for the past 38 years. The lowest pressure was 29.319 ins. on July 24th, as against 29.208 ins. in 1920 and 28.735 ins. for the past 38 years.

The temperature of the air was moderately above normal in February, March, April, August and December and moderately below in January. The mean temperature for the year was 72°.2, as against 72°.0 in 1920 and 71°.8 for the past 38 years. The highest temperature was 92°.2 on August 22nd as against 93°.1 in 1920 and 97°.0 for the past 38 years. The lowest temperature was 44°.0 on February 4th, as against 45°.1 in 1920 and 32°.0 for the past 38 years.

The rainfall was very considerably above normal in May, and moderately above normal in March, August and September. It was considerably below normal in April, October, November and December. The total for the year was 97.340 ins., as against 107.880 ins. in 1920 and 84.620 ins. for the past 38 years. The greatest fall in one civil day was 6.060 ins. on September 3rd and the greatest in one hour was 3.250 ins. between 1.30 p.m. and 2.30 p.m. on May 31st.

The wind velocity was considerably below normal in January, March, April, May and October. In July it was normal and in the remaining months it was slightly below normal. The mean velocity for the year was 10.7 m.p.h., as against 12.0 m.p.h. in 1920 and 12.7 m.p.h. for the past 38 years. The maximum velocity for one hour as recorded by the Beckley Anemograph was 51 miles at 11 a.m. on July 24th, as against 51 miles in 1920 and 108 for the past 38 years. The maximum squall velocity, as recorded by the Dines-Baxendell Anemograph, was at the rate of 69 m.p.h. at 5 h. 53 m. a.m. on September 3rd, as against 61 m.p.h. in 1920 and 105 m.p.h. for the past 12 years.

The climate of Hongkong is similar in its broad features to that of Kowloon and the New Territories, but at the higher levels, from 1,400 to 1,800 feet above sea level the temperature is usually from 3° to 8° lower than at the Observatory, Kowloon. The humidity is usually greater than in Kowloon and approaches saturation for several days at a time during March and April when mist is very prevalent. In summer the city of Victoria, and the rising terraces behind it, derive little or no benefit from the S.W. monsoon, being sheltered by steep hills from S.E. to S.W. In winter it is exposed to the N.E. monsoon which occasionally blows along the harbour through Lyemun Pass with considerable violence. On the other hand the S.W. side of the Island is protected from the N.E. monsoon in winter and enjoys the benefit of the S.W. monsoon in summer.