Tuífua Vailena | 22 October 2026

Every island group in Tonga could be in drought by the end of this month, the Kingdom’s Meteorological Service has warned.

In its September drought outlook, the service put the chance of very dry conditions across Tonga from September to November at 80 to 100 percent. It said a very strong El Niño could develop towards the end of the year.

The World Meteorological Organization says El Niño is strengthening in the tropical Pacific and is expected to last into early 2027.

The Met Service projected that all six island groups monitored for drought (Tongatapu, ʻEua, Haʻapai, Vavaʻu, Niuatoputapu and Niuafoʻou) could reach drought declaration status by the end of October.

When the outlook was issued, four groups were already under drought declarations: Tongatapu, Haʻapai, ʻEua and Niuatoputapu. Niuafoʻou was under a drought warning and Vavaʻu was under a drought alert. RNZ Pacific reported on 9 October that those classifications had not changed. The Met Service had not published an October update at the time of publication.

These are meteorological drought classifications. They are not the same as declaring a national disaster.

Seluvaia Ilolahia, the Met Service’s chief climate officer, told RNZ Pacific that Tonga is going through serious drought conditions. She said some rain had fallen in Vavaʻu, but the rest of the country had been below average. The warnings will stay in place for the next three months, she said.

She said El Niño was still very strong and was likely to peak around November to December. But she warned that the dry weather’s effects could last well beyond that.

“The impacts might come later, even after the event, we will still feel it,” Ilolahia said.

Months of low rain

Rain has been scarce for months. In June, Niuatoputapu received just 10 millimetres, about 93 percent less than usual, according to the Tonga Meteorological Service. Haʻapai’s rainfall was down by about 80 percent. Only Vavaʻu had more rain than normal.

The dry weather continued through July and August.

The four island groups already in drought are home to about 85 percent of Tonga’s people.

Tonga has seen this pattern before. One of the strongest El Niño events on record, in 1982–83, shows how much damage these events can do, and why early warning matters.

Factbox: June rainfall by station

Source: Tonga Meteorological Service. Compared with the service’s 30-year June averages.

What the 1982–83 El Niño taught forecasters

El Niño is a shift in the Pacific Ocean that happens every few years. The trade winds weaken, warm water spreads east, and rain patterns across the Pacific change. For Tonga, it usually means less rain.

The 1982–83 event is the subject of an ABC documentary, presented by Matt Bevan for the If You’re Listening series. It looks at what happened and how scientists learned to see such events coming.

Australia went into severe drought in 1982. Farmers had to cut livestock numbers because there was not enough feed or water. On 8 February 1983, a huge dust storm swept over Melbourne. Eight days later, the Ash Wednesday bushfires killed 75 people and destroyed or badly damaged about 2,000 homes.

The effects were different elsewhere. Indonesia suffered drought, while parts of South America flooded.

The documentary’s main lesson is that communities were largely unprepared. Reliable seasonal forecasts did not yet exist.

That began to change through the work of Australian scientists Neville Nicholls and John McBride. They studied the Southern Oscillation Index, a measure of the difference in air pressure between Tahiti and Darwin. Their research showed that changes in Pacific air pressure could help predict rainfall months ahead. It became an important foundation for the seasonal forecasts used today, including the drought outlooks issued by the Tonga Meteorological Service.

The documentary also looks at research suggesting climate change could make extreme El Niño events more frequent or more intense.

But it adds a warning. The 2023 El Niño did not bring the severe Australian drought that some had expected.

El Niño makes dry conditions more likely. It does not guarantee them. That is why forecasters look at the full seasonal outlook, not a single indicator.

For Tonga, the difference from 1982 is that the warning has already come. The question is what has been done with it.