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GEOGRAPHY AND CLIMATE
the latter part of the month, widespread fog was experienced on many days and as a result, 24 incoming aircraft were diverted from Hong Kong Airport.
Five troughs of low pressure passed the Colony in May and were all accompanied by rain or thunderstorms. However, these systems did not stay long over Hong Kong and the total rainfall for the month was below average.
Although unsettled weather with occasional showers and wide- spread thunderstorms affected Hong Kong for 11 consecutive days during June, there was no serious flooding or landslides. The month's weather was quite normal in every respect.
Rain was reported on every day of July and this sets a new record of rain days for the month. Four tropical cyclones formed in the western Pacific and the South China Sea but only one, Typhoon Viola, came close enough to cause strong winds in Hong Kong.
Typhoon Viola formed on July 22 about 340 miles south of Guam. It moved north-westwards at first and then turned west-north-west, entering the Bashi Channel on July 27. The typhoon crossed the China coast about 120 miles east of Hong Kong the next morning and turned onto a more westerly track. It weakened slowly overland and, in Hong Kong there were strong south-west winds for several hours as Viola passed by about 60 miles to the north.
Although no tropical cyclones affected the Colony directly in August, the heavy rain on the 10th and 11th of the month could be attributed to typhoon Betty which crossed the coast of China near Foochow on August 8 and persisted as an area of low pressure over central China during the next two days. 220.8 mm (8.69 inches) of rain fell on August 11 and this is the second highest daily amount recorded in any August. On the same day the strong monsoon signal (the black ball) was hoisted for almost 13 hours to give warning of the south-westerly monsoon. Gusts of 51 knots were recorded at both Waglan Island and Tate's Cairn.
No. 1 local storm signal was hoisted on three occasions in Septem- ber and early October but none of the tropical cyclones came close enough to affect the Colony. The total rainfall for September and