Suwarrow, declared a national park in 1978, is one of the Cook Islands’ most protected environments. NES/25092321
A tropical depression is set to strengthen into a Category 1 cyclone today, triggering severe weather warnings across the Cook Islands as officials urge residents to prepare for damaging winds and heavy swells.
TD01F, located close to Suwarrow yesterday, is expected to develop into a Category 1 tropical cyclone today, bringing damaging gale-force winds, heavy rain and dangerous swells to parts of the Cook Islands.
In a special weather bulletin issued at 5.15pm yesterday, the Cook Islands Meteorological Service said a tropical cyclone warning was in force for Suwarrow.
“A tropical cyclone alert remains in force for Palmerston, Aitutaki and nearby islands,” according to the weather bulletin issued yesterday. “TD01F is expected to strengthen and may develop into a Category 1 Tropical Cyclone within the next 12-18 hours.”
The weather office said that at 2pm yesterday, the system was located approximately 10.4 degrees south, 163.8 degrees west – about 328 kilometres north-northwest of Suwarrow – with winds near its centre of around 30 knots (55 km/h).
For Suwarrow, strong east-to-southeast winds of 20 to 25 knots (37–46 km/h) with gusts up to 35 knots (64 km/h) were expected to increase to damaging gale-force winds starting late last night. Winds were forecast to reach around 35 knots (65 km/h) with gusts up to 50 knots (93 km/h). Frequent and heavy rain, squally thunderstorms, very rough to high seas and damaging heavy swells were also forecast.
For Pukapuka and Nassau, fresh to strong east-to-southeast winds of 20 to 25 knots (37–46 km/h) with gusts to 35 knots (64 km/h) were forecast. The islands were also expected to receive periods of rain – heavy at times – with squally thunderstorms, as well as rough to very rough seas with moderate to heavy swells.
Palmerston, Aitutaki and nearby islands were put on a tropical cyclone alert, with winds expected to strengthen over the next 24 to 30 hours, the weather office said yesterday.
“Rain and thunderstorms are expected to develop and become frequent and heavy. Seas will become rough to very rough, with damaging heavy swells. Damaging gale-force winds are possible from later Saturday.”
For the remaining Southern Cook Islands, including Rarotonga, moderate to fresh east-to-southeast winds – becoming strong and gusty over the weekend –have been forecast. The forecast also includes cloudy periods with occasional showers, becoming frequent and heavy at times, and rough seas with moderate to heavy swells.
The remaining Northern Cook Islands are expected to experience fresh to strong northeasterly winds with gusts up to 64 km/h, cloudy periods with occasional heavy showers and rough to very rough seas with moderate to heavy swells.
The Meteorological Service has advised the public to secure loose items around their homes and properties, check emergency supplies and ensure their households are prepared.
“Residents of Palmerston, Aitutaki and nearby islands should prepare for worsening conditions,” the weather office said.
“Fishermen, boat operators and inter-island vessels should closely monitor marine forecasts and avoid going to sea if conditions are unsafe.”
Emergency Management Cook Islands (EMCI) also advised the public to take note of the latest weather warnings issued by the Meteorological Service.
“EMCI advises the public, particularly those in the Northern Group, to secure loose outdoor items and take precautions during strong winds, avoid unnecessary sea travel and exercise caution around coastal areas and stay informed through official weather updates and advisories.”
The latest weather warning comes after the 2026/27 Tropical Cyclone Outlook, coordinated by Earth Sciences New Zealand, predicted increased cyclone activity for the Southwest Pacific region, which includes the Cook Islands.
The Tropical Cyclone Outlook expects that seven to 11 named tropical cyclones could occur in the Southwest Pacific over the season. The official tropical cyclone season starts on November 1.
Dr Andrew Lorrey, Earth Sciences New Zealand Principal Scientist – Climate and Environmental Applications, said that there are strong indications that the Southwest Pacific is likely to see an increase in cyclone activity relative to recent years.
“Over the long term, cyclone numbers have been gradually decreasing in the Southwest Pacific, but there can be prominent year-to-year variability. Extended weather forecasts indicate we may also have an early start to the tropical cyclone season in the region this year,” Dr Lorrey said.
“Communities across the Pacific should pay attention to forecasts and heed official advice if a weather warning related to a tropical cyclone is issued.”
Cook Islands Meteorological Services director Maara Vaiimene said this tropical cyclone season officially runs from November through April and is expected to occur under the influence of an El Niño weather condition.
“Historically, El Niño tends to shift tropical cyclone activity further east across the Southwest Pacific, potentially increasing the risk of tropical cyclones affecting areas closer to the Cook Islands,” Vaiimene told the Cook Islands News.
“While seasonal outlooks indicate the overall level of risk, they cannot predict exactly where or when a cyclone will occur. It is important to remember that it only takes one tropical cyclone to have a major impact on communities.
“For that reason, all households are encouraged to review their emergency plans, including the Tropical Cyclone tracking map normally printed in the Vodafone Directory, secure their homes, and ensure emergency supplies are ready ahead of the season.”
El Niño impact
Cook Islands is currently under the influence of El Niño weather conditions causing below-normal rainfall, which has continued to strengthen across the tropical Pacific during 2026.
In September, only 31 millilitres of rain were collected in the Nikao area. In 2025, 106mm and in 2024, 176mm of rain were collected in September for the same area. The office recorded 62mm of rain in July and 96mm in August.
In Titikaveka, 59mm of rain fell in September this year compared to 59mm and 97mm for the same month in 2024 and 2025. In July, 72mm of rain and on August 96mm of rain were recorded for the area.
Vaiimene said communities across the Cook Islands are already experiencing drier-than-normal conditions, and low rainfall may continue into the coming months, although periodic rainfall events can still occur.
He added that there was a risk of uncontrolled bush fires with the dry and windy conditions so community needs to be vigilant in these activities.
“Rainfall distribution has varied between islands; however, many parts of the Southern Group have experienced below-average rainfall conditions consistent with the developing and strengthening El Niño pattern in the tropical Pacific,” Vaiimene said.
Current regional climate guidance indicates that the present El Niño is expected to continue through the remainder of December 2026 and into early February 2027.
Dry conditions may continue across much of the Southern Cook Islands over the coming months, although early to late evening light showers will be experienced through the coming months.
According to Vaiimene, the potential impacts include reduced water availability and increased pressure on household and community water supplies, stress on crops and livestock due to limited soil moisture, increased risk of drought conditions if rainfall deficits persist, greater susceptibility to vegetation and bush fires during extended dry periods and possible impacts on ecosystem health and freshwater
“We encourage everyone to remain mindful of water use, stay connected to official weather updates, and take practical steps now to prepare their homes and families,” Vaiimene said.
“Working together as a community will help us better manage whatever the weather brings.”