2022 was Singapore's wettest year on record
SINGAPORE: With above-average rainfall for most months, it was a very wet 2022 for Singapore, which also saw temperature levels reach new highs in some categories.
In its annual climate assessment report released on Thursday, the Meteorological Service Singapore Met Service said the average annual rainfall for 2022 was nearly 18.8 per cent above the long-term average between 1991 and 2020.
This was partly influenced by the prevailing La Nina conditions, along with a negative Indian Ocean Dipole, which refers to a broad pattern of temperature differences in the western and eastern Indian Ocean.
The sixth wettest year in the past 40 years and the tenth warmest year since 1929 was the 2022 year.
October was the wettest month in the year, with total rainfall of 412 mm - about twice the month's long-term average.
This exceeded the previous high of 389.3 mm in 2011, making October 2022 the wettest October in the last four decades.
The highest daily rainfall for the month was 138.1 mm, recorded at Pasir Panjang.
It is not common for the year's wettest month to fall in October, with the previous occurrence in 1985, the Met Service said.
The weather in October 2022 was exceptionally wet, with a high number of Sumatra squalls affecting Singapore.
Several tropical cyclones had formed in the South China Sea and Western Pacific Ocean, contributing to the formation of these squalls. The convergence of winds in the area caused by these cyclones resulted in the formation of Sumatra squalls, which typically bring widespread showers and gusty winds to Singapore in the early morning hours.
March 2022 was the wettest March since 2009, it added.
The wet weather in March 2022 was due to the strong solar heating of land areas and the convergence of winds over the island.
Most parts of the island received above-average rainfall in March, making it one of the wettest months of 2022.
The second wettest day in March in 10 years, with the highest daily total rainfall of 134.2 mm recorded at Jurong West, resulted in thundery showers over southwestern Singapore on Mar 7, 2022.
The above-average rainfall in both 2021 and 2022 has led to questions about whether this increase represents a long-term trend in Singapore's climate.
The Met Service said that the trend is not considered statistically significant, although there has been a gradual increase in the annual total rainfall of Singapore by 78 mm per decade from 1980 to 2022.
The years that have typically experienced La Nina conditions, such as 2022, 2021 and 2011 tend to be wetter, while years with El Nino conditions, such as 1982, 1997 and 2015, tend to be drier, it added.
The Met Service also noted that 2022 marked the third year in a row where La Nina conditions were present, making this the first triple year La Nina since at least the 1960 s.