F 5
barometric pressure, temperature of the air and of evaporation and the amount of cloud are made at each hour of Hongkong 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 1924 were :-
(a) Absence of typhoons.
(b) Heavy rain in May, June, July and August.
(c) A heat wave from August 28 to September 10.
Barometric pressure was considerably below normal in February, particularly from the 6th to the 10th and from the 18th to the 23rd. It was moderately above in March and moderately below in April, gradually regaining normal by August. It was moderately above normal in September and November. The mean pressure for the year at station level was 29.830ins. as against 29.828ins. in 1923 and 29.842ins. for the past 41 years. The highest pressure was 30.314ins. on November 24 as against 30.311ins. in 1923 and 30.509ins. for the past 41 years. The lowest pressure was 29.365ins. on July 15, as against 28.590ins. in 1923, the lowest on record.
The temperature of the air was moderately above normal in January, February, May and September, and slightly below in March, April, June, November and December. The mean temperature for the year was 72.3 as against 72.5 in 1923 and 71.9 for the past 41 years. The highest temperature was 93.2 on September 7, as against 92.9 in 1923 and 97.0 for the past 41 years. The lowest temperature was 47.5 on January 1 as against 45.7 in 1923 and 32.0 for the past 11 years. The heat wave from August 28 to September 10 was exceptional. The mean temperature for September 7, 87.5 was the highest on record for any month and the maximum on this day, 93.2, has only been exceeded in September on two occasions, namely on September 6, 1895, when it was 94.0 and on September 17, 1892, when it was 93.9. The night of September 7-8, was the hottest on record for any month, the minimum being 84.3. The next hottest was 1915, August 7-8, when the minimum temperature was 83.7.