Home / PRESS RELEASE / ENGLISH VERSION / El Niño Watch for Tonga (13 August 2018)

El Niño Watch for Tonga (13 August 2018)

E-mail Print PDF

15th August, 2018 TONGAN



The consensus from international climate models is for the tropical pacific to transition towards El Niño in the next three-month period (a 55% chance over August-October 2018). The probability for El Niño conditions increases in to 2019, with a 78% chance for El Niño conditions over February – April 2019. The strength and characteristics of this event – if it happens – remain uncertain at this point, but indications so far are that it is unlikely to be in the strong category. The effects of El Niño on Tonga usually include cooler night time temperatures, lower rainfall during the rainy season and increase in the frequency of tropical cyclone occurrence.

What is El Nino?

El Niño is the movement of warm ocean water from the north of Australia to the South American coast along the tropics. It brings warmer than normal water to the central and eastern tropical Pacific which usually results in changes in weather and climate. El Niño is a natural occurrence and happens about every 3 to 7 years.

Current Situation

The tropical Pacific Ocean surface temperature is currently at levels typically associated with a weak El Niño. Although atmospheric patterns have continued to remain neutral across the tropical Pacific during July 2018. changes have occurred in the atmosphere that may be a response to the warm ocean waters and trade winds have weakened. However, these changes would need to persist for several more weeks in order to confirm beyond doubt that an El Niño has developed.

Effects of El Niño on Tonga’s Climate

El Niño events normally last for around a year; however they can be shorter, or last much longer depending on the nature of the event. The effects of El Niño on Tonga usually varies but for most of the time it brings cooler dry seasons (like we are experiencing now) and drier wet seasons than normal and more cyclones. Usually Tonga is affected by 1 cyclone per year but increases to around 2 during El Niño.

Previous El Niño Events

The worst droughts to be recorded in Tonga in recent history happened during El Niño Years. The 1982-83 and the 1997-98 caused water shortages to a point where water had to be distributed to the islands of Ha’apai and caused food shortages as a result of devastation to Agriculture. Tropical Cyclone “Isaac” (Category 4 Cyclone that affected most of Tonga Islands and most costly on record) and Tropical Cyclone “Ron” (Category 5 Cyclone, strongest ever recorded in Tonga’s history affected Niuafo’ou) occurred in 1982 and 1997 respectively. The drought during the 2015-2016 El Niño very much affected agriculture and various climate sensitive sectors in the country and about 5 cyclones affecting part of the country during the cyclone season.

Recommended actions for the next 3 months

Planners are encouraged to start planning for the possible El Niño development in the coming 3 months. Particular attention should focus on rainfall and tropical cyclone sensitive sectors such as Agriculture and Fisheries (Food Security), Health, Water Resource Management and Tourism.

The public are encouraged to seek advice from the relevant authorities e.g. Ministry of Agriculture on the best practices to minimise the effects of El Niño.

Citizens are also encouraged to follow the El Niño Advisories over the coming months issued by the Meteorological Service. The next El Niño Advisory will be issued in early September 2018.

Contact & Further information

For further information contact the Meteorology Division of the Ministry of Environment, Energy, Climate Change, Disaster Management, Meteorology, Information and Communications at Telephone 35355 or Email  This e-mail address is being protected from spambots. You need JavaScript enabled to view it . More information is also available at www.met.gov.to


Issued by the: Ministry of Meteorology, Energy, Information, Disaster Management, Environment Climate Change & Communication, P.O. Box 1380, Level 2, O.G Sanft Building, Nuku’alofa, Tonga. Tel: (676) 28170 Fax:  (676) 24861; Email: This e-mail address is being protected from spambots. You need JavaScript enabled to view it , Websites: www.tongaportal.gov.to

Last Updated ( Wednesday, 15 August 2018 15:51 )  

Who's Online

We have 494 guests online