Rarotonga (Cook Islands) weather in January

January in Rarotonga: hot, soaked, with clean air — fine if you can take 18 rainy days.

Updated September 2026 · climate normals from ERA5 reanalysis

Rarotonga Cook Islands · South Pacific · Island78
  1. 78Jan
  2. 74Feb
  3. 77Mar
  4. 81Apr
  5. 74May
  6. 83Jun
  7. 80Jul
  8. 81Aug
  9. 85Sep
  10. 84Oct
  11. 87Nov
  12. 79Dec

#9 of 12 months in Rarotonga · #528 of 1413 destinations to visit in January · comfort 78/100 (tier B)

Days
28°C
Nights
22°C
Wet days
18
Sun
10.4 h
Humidity
81%
Daylight
13 h
Rarotonga, Cook Islands
Photo: Wikimedia Commons · Public domain

Traveller notes on Rarotonga in January

Other months in Rarotonga

Regulars are specific this counts as the coldest month of the year here on paper, though conditions can still run genuinely warm and pleasant with no particular cold snap in a given year, part of the broader April-to-November dry, cooler season. Our row backs that mild, genuinely wet and windy read, 23.9C over 17.7C nights feeling 15C, with a substantial 104.1mm of rain across 10.2 days and a real 30.5 kph wind. Regulars are consistent which side of the island you're on matters a lot, the northeast staying meaningfully more sheltered while Muri and the east/southeast catch the colder trade wind directly. This also counts as a good month for whale watching along the corridor from Avarua harbour to the Edgewater. The sea sits at a cooler but still swimmable 25C. The record: 9 hours of sun and AQI 42.
ColdestOnPaperOftenStillWarmPleasant · August · 1 month ago · Read more on Tripadvisor ↗
The rainy season here runs November to April, and regulars are clear that April is its tail end - much less rain than January or February, most of what does fall arriving overnight, with short refreshing showers by day and plenty of fine ones between them. The trade winds mean the island splits in two on any given afternoon: one side gets the shower, the other stays in the sun. Our row shows the easing rather than an arrival - 27.2C over 21C, humidity beginning to drop from its wet-season peak, with 136.5mm across 16.3 days and a 27.6C lagoon. No cyclone risk left to speak of by this point in the season. The record: 9.5 hours of sun, a 29.2 kph wind and AQI 39.
OneSideShowersOtherSideSun · April · 1 month ago · Read more on Tripadvisor ↗
June is winter here and regulars treat that as a real thing rather than a joke: cool days, chilly nights, and warm clothing needed after dark, while still being mild next to New Zealand. Their figures are our row to the degree - mid-to-high 70s by day and mid-60s at night against our 24.8C over 18.5C. The sea can feel cold, though the lagoon at low tide in sun is comfortable once you are moving. Two details make the month concrete: the prevailing south-easterly blows hard enough to make the Muri and Titikaveka stretch the chilly side of the island, and the sun sets around six, so the evenings are long and cool. The record: 73.4mm across 9.6 days, 8.8 hours of sun, a 30.8 kph wind and a 25.3C sea.
TheMuriSideIsTheWindwardOne · June · 1 month ago · Read more on Tripadvisor ↗
October ends the Rarotongan dry season and residents call it unpredictable in the fullest sense: you might get a week of rain or a week of clear sun. Our row's 115.9mm across 9.2 days is about thirteen millimetres a wet day, so when it comes it means it. Days warm to 24.7C. The detail they always add is the nights, which drop below 20C - ours is 18.6C reading as 17C - so pack one long-sleeved jumper even for a tropical island. The south-easterly trades keep running and the spring wind picks up from mid-September, which our 31.8 kph average confirms; the lagoon has not warmed up yet at 24.2C. In exchange it is shoulder season and quiet. The record: humidity 75 percent, 10 hours of sun and AQI 47.
BringOneJumperAnyway · October · 1 month ago · Read more on Tripadvisor ↗

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Rarotonga climate normals — January

Daytime high28°C / 82°F🥵 hot
Nighttime low22°C / 71°F
Feels like (high)30°C / 86°F
Sea temperature27°C / 80°F😎 warm sea
Rainfall197 mm / 7.8 in⛈ soaked
Rainy days18 days
Humidity81%💦 very humid
Dew point21°C / 70°F
Sunshine10.4 h/day
Daylight13.2 h
Wind28 km/h / 18 mph
Air quality (US AQI)35🍃 good

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Rarotonga in January

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

BusyNew Zealand summer holidays, school holidays in 4 of the markets that fill it(estimated)

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Peak crowdsBusyShoulder seasonQuiet

Best months for Rarotonga's weather

Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).

Fair weatherRarotonga's weather doesn't swing hard through the year — comfort stays fairly steady in every month.

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What's on in Rarotonga in January

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Hazard

    Cyclone season

    1 Nov – 30 Apr

    The South Pacific cyclone season runs from November to April, peaking between December and February. Most years pass without a hit, and the wet months are the cheapest to visit. Source ↗

  • Holiday

    New Zealand summer holidays

    19 Dec – 27 Jan · usuallySchool holidaysCrowded

    The island is a four-hour flight from Auckland, so the Christmas break fills the beachfront rentals despite it being the wet half of the year. Rates peak either side of New Year. Source ↗

What's on around the world in January →

Nearby, and something's on

Within 300 km of Rarotonga — a day trip or a short hop — with something on this month. Never part of the comfort score.

Where is Rarotonga?

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Rarotonga in January — FAQ

Is January a good time to visit Rarotonga?
January in Rarotonga: hot, soaked, with clean air — fine if you can take 18 rainy days. It ranks #9 of 12 months for Rarotonga on SeasonMap's comfort score (78/100).
What is the weather like in Rarotonga in January?
In January, Rarotonga averages a daily high of 27.7°C and a low of 21.7°C, with about 196.9 mm of rain over roughly 17.5 rainy days.
What is the air quality in Rarotonga in January?
Rarotonga has a mean US Air Quality Index of about 35 in January.

Within 300 km: Avarua's New Zealand summer holidays around 19 Dec – 27 Jan.