F 3
It is hoped that the meteorological observations at the Peak Signal Station, to which reference was made in last year's report, will be commenced shortly.
III. METEOROLOGICAL OBSERVATIONS AT THE OBSERVATORY.
Automatic records of the temperature of the air and evaporation were obtained with a Richard dry and wet bulb thermograph, and of the direction and velocity of the wind with a Beckley and a Dines-Baxendell anemograph, modified as described in the report for 1912. The amount of rain is recorded automatically by a Nakamura pluviograph, the amount of sunshine by a Campbell-Stokes universal sunshine recorder, and the relative humidity of the air by a small Richard hair hygrograph. Eye observations of barometric pressure, temperature of the air and of evaporation and the amount of cloud are made at each hour of Hong Kong Standard time. The character and direction of the motion of the clouds are observed every three hours. Daily readings are taken of self-registering maximum and minimum thermometers.
Principal Features of the Weather. The principal features of the weather in 1920 were:-
(a) Barometric pressure below normal from the beginning of May to the beginning of August.
(b) Rainfall much above normal in May, July and November.
Barometric pressure was considerably below normal in May, June, July, November and December and moderately above in January. The mean pressure for the year at station level was 29 ins. 814 as against 29.842 in 1919 and 29.843 for the past 37 years. The highest pressure was 30.374 on January 4th as against 30.398 in 1919 and 30.509 for the past 37 years. The lowest pressure was 29.208 on July 19th as against 29.287 in 1919 and 28.735 for the past 37 years.
The temperature of the air was moderately below normal in April and considerably above normal in November and December. The mean temperature for the year was 72°.0 as against 72°.2 in 1919 and 71°.8 for the past 37 years. The highest temperature was 93°.1 on July 25th as against 92°.2 in 1919 and 97°.0 for the past 37 years. The lowest temperature was 45°.1 on January 5th as against 39°.4 in 1919 and 32°.0 for the past 37 years.
The rainfall was considerably above normal in May, July and November. The total for the year was 107 ins. 880 as against 76.140 in 1919, and 84 ins. 276 for the past 37 years. The greatest fall in one civil day was 8 ins. 235 on July 19th and the greatest in one hour was 1 ins. 435 between 8.30 p.m. and 9.30 p.m. on September 12th.