The year 2001 was warmer and wetter than usual. The mean temperature of 23.6 degrees was 0.6 degree above normal, ranking the fourth highest on record. The mean minimum temperature of 21.8 degrees was the second highest on record. The annual total rainfall of 3091.8 millimetres also ranked the fourth highest. In June 2001, the total rainfall of 1083.6 millimetres set a new record for the month. Six tropical cyclones necessitated the hoisting of Tropical Cyclone Warning Signals. The No. 8 signal was hoisted during the passage of Typhoon Utor and Typhoon Yutu. The only Black Rainstorm Signal of the year was issued on September 1 while the Red Rainstorm Signal was issued on nine occasions.
During the passage of Typhoon Utor on July 6, the storm surge coupled with astronomical high tide brought the sea level at Quarry Bay to 3.4 metres, the highest recorded in Victoria Harbour since Typhoon Wanda in 1962.
January was warmer and wetter than usual.
February was again warmer but drier than usual.
Warmer and drier weather continued into March. The rainstorm on March 25 necessitated the issuance of the Amber Rainstorm Warning, the earliest rainstorm warning in a year since the revised rainstorm warning system came into effect in 1998.
April was again warmer and drier than usual. Hail fell on April 9 during the passage of thunderstorms.
May was the fourth consecutive month with warmer and drier weather. The accumulated rainfall since January 1 amounted to only 410 millimetres, 33 per cent below the normal figure .
With an active trough of low pressure lingering over the vicinity of the south China coast for about two thirds of the month, the weather of June was marked by persistent heavy rain and thunderstorms. The monthly rainfall amounted to 1083.6 millimetres, about three times the normal figure. This is also a new rainfall record for June, the previous record being 962.9 millimetres in June 1966.
In June, Typhoon Chebi led to the hoisting of the Standby Signal No. 1 in Hong Kong for the first time this year. Tropical Storm Durian, which developed into a full-fledged typhoon in early July, affected Hong Kong by the end of June and necessitated the hoisting of the Strong Wind Signal No. 3.
July was wetter and cooler than usual. A waterspout formed over the Tathong Channel during the passage of Durian. Typhoon Utor and Typhoon Yutu both necessitated the hoisting of the No. 8 signal in Hong Kong. The last time the No. 8 signal was hoisted twice in July was in 1966.
It was warmer and drier than usual in August. Standby Signal No. 1 was hoisted for Tropical Storm Fitow.
September was warmer and wetter than usual. Typhoon Nari, characterized by its erratic movement and unusual long life-span of 15 days, necessitated the hoisting of the No. 3 signal in Hong Kong.
It was warmer and drier than usual in October.
Dry weather continued into November with only 4.3 millimetres of rainfall recorded against a normal of 35.1 millimetres.
December was warmer and wetter than usual.