THIRUVANANTHAPURAM : Kerala in 2023 recorded 24% deficit rainfall, its worst since 2017. The state received 2,202mm of rain in the just-concluded year against the normal 2,890mm.
The only silver lining was that the state, despite experiencing one of its driest periods, escaped from setting the record for the worst rainfall ever thanks to a surplus northeast monsoon. The monsoon, ending on December 31, contributed an additional 27% of rainfall, with the state receiving 624mm of rain compared to the normal 492mm since October.
According to weather experts, a good monsoon at the end of the year helped the state avoid recording the worst rainfall deficit in history.
“Kerala recorded the worst rainfall deficit in 2016 (an El Nino year) marked by a poor northeast monsoon season. Though 2023 was also an El Nino year like 2016, the northeast monsoon this time tried to compensate for previous deficits,” said Rajeevan Erikkulam, a meteorologist with Kerala State Disaster Management Authority.
Rainfall seasons are divided into winter (January and February), pre-monsoon (March-May), southwest monsoon (June-September ) and northeast monsoon (October-December). The first and second seasons saw a deficit of over 20%. This year’s southwest monsoon, which usually accounts for 70-80% of the state’s total annual rainfall, turned out to be the worst in the past 50 years, with a deficit of 34%.
Rajeevan said the deficit of nearly 50% in Wayanad is a cause for concern while southern districts like Idukki made up for the deficits with surplus rainfall during the northeast monsoon. Only Wayanad and Kannur received less rainfall (-4% departure each) during the northeast season while Pathanamthitta, Thiruvananthapuram, Kottayam, Alappuzha and Ernakulam received large excess or excess rainfall.
El Niño, a climate pattern characterised by periodic warming of sea surface temperatures in the equatorial Pacific Ocean, posed a potential threat to the monsoon. However, weather experts noted that its impact was counterbalanced by a favourable sea surface condition known as the Indian Ocean Dipole (IOD), contributing to increased rainfall in the October-December period.