March 2018 was one of Hong Kong’s warmest on record
Weak winter monsoon behind ‘unseasonable’ high temperatures and bright sunshine with little rain
This March was one of the warmest on record in Hong Kong thanks to a relatively weak northeast monsoon, the Hong Kong Observatory said.
The month was “unseasonably warm” and sunny with little rain, with a monthly mean maximum temperature of 24.4 degrees Celsius, the highest since records began in 1885, tying with the reading in March 1960.
The monthly mean temperature last month was 20.8 degrees – 1.7 degrees higher than the normal figure of 19.1 degrees – making it the fourth highest on record, after March 2002 (21.5 degrees), March 1987 (21.3 degrees) and March 1960 (21.2 degrees).
March 1973 shared fourth place with the same monthly mean temperature.
The total duration of bright sunshine in March this year was 196.2 hours, more than twice the normal figure of 90.8 hours.
Total rainfall was 22.7 millimetres, only about 28 per cent of the normal figure of 82.2 millimetres.
The accumulated rainfall of 89.4 millimetres since January 1 this year was about 45 per cent below the normal figure of 161.3 millimetres in the period.
The Observatory’s scientific officer Andy Lai Wang-chun said the warmth and sunshine was due to a weaker than usual winter monsoon.
“It was mainly because the northeast monsoon that affected southern China was rather weak. The upper-air southerly wind was also relatively weak, leading to less moisture transport than usual.”
The reduced moisture in turn cut the amount of cloud, Lai said.