What is the Weather Like in Rarotonga and the Cook Islands in August?
There’s a reason why Rarotonga and the Cook Islands are such popular holiday destinations in August. For Americans, the Cook Islands’ warm weather and cool sea breeze offer relief from the Northern Hemisphere summer, while Australians and New Zealanders can escape the winter. For these reasons, August is one of the busiest months in the Cook Islands. Even if it is a little busier in the Cook Islands during August, the allure of the warm sunny days, warm sea temperatures and awesome conditions for snorkelling and scuba diving understandably might draw you in anyway. If that’s the case, take a look at our guide to the Rarotonga and Cook Islands weather in August.
Before we jump into this weather guide for August, be sure to bookmark Rarotonga & the Cook Islands Weather, Seasons & Climate and The Best Time to Visit the Cook Islands for more advice.
6 Tips for Visiting the Cook Islands in August
- August is one of the most popular months to visit the Cook Islands, so book accommodation well in advance to avoid disappointment
- The nights feel considerably cooler than the day, so be sure to pack a light jacket – you’ll also be thankful to have this on boats too
- August is in the middle of the whale watching season, which you can learn more about in The Best Time to See Whales in the Cook Islands
- Be sure to apply high-factor reef-safe sunscreen regularly
- Note that August 4 is Consitution Day in the Cook Islands, a public holiday where some businesses are closed
- August is considered a safe time to visit the Cook Islands with little risk of cyclones.
Typical Temperatures in August
Temperatures are dropping in Rarotonga and the Cook Islands in August, which might feel cool for the locals but travellers from colder climates find it comfortable and soothing. Rarotonga and Mangaia are the coolest islands during this time, while it’s a little milder in Aitutaki and warmer still in the Northern Group. Sea temperatures are at their coldest of the year but are still totally swimmable.
Temperatures Across the Cook Islands
- Rarotonga – The average maximum temperature is 25°C / 77°F and the minimum average temperature is 19°C / 66°F
- Aitutaki – The average maximum temperature is 27°C / 81°F and the minimum average temperature is 21°C / 70°F
- Mangaia – The average maximum temperature is 25°C / 77°F and the minimum average temperature is 19°C / 66°F
- Mitiaro – The average maximum temperature is 27°C / 81°F and the minimum average temperature is 20°C / 68°F
- Manihiki (North) – The average maximum temperature is 30°C / 86°F and the minimum average temperature is 24°C / 75°F
- Penrhyn (North) – The average maximum temperature is 30°C / 86°F and the minimum average temperature is 24°C / 75°F.
Sea Temperature in August
Rarotonga and the Cook Islands have warm sea temperatures all year round but have the coldest temperatures in August at 24°C / 75°F.
Hours of Sun in August
The great thing about Rarotonga and the Cook Islands in winter is that the days are relatively long. The average hours of daylight are 11 hours per day, while sunshine hours are usually around 2.8 hours. This means that most days aren’t particularly sunny in August.
UV Levels During August
After usually experiencing relatively mild UV levels in the previous two months, the Cook Islands’ UV levels start to rise again in August. The UV level in August is typically around 8 UV index around midday. It’s a good idea to apply high-factor sunscreen throughout the day. For advice on what sunscreen to use, check out The Best Sunscreens for the Cook Islands + Sun Protection Tips.
Sunrise and Sunset During August
August has daylight hours lasting about 11 hours a day in the Cook Islands.
- Sunrise: 7.10 am at the beginning of August and 6.49 am at the end of August
- Sunset: 6.21 pm at the beginning of August and 6.30 pm at the end of August.
Learn about the local time zone in What is the Rarotonga & the Cook Islands Time Zone?
Rainfall in August
Even though it’s in the dry season, August still has a few rainy days. There are fewer days of rain compared to many other months but August can still have heavy showers on occasion.
The Cook Islands receives an average of 152 mm / 6″ of rainfall in the month of August, with only around 3 days of the month experiencing rain.
Average Rainfall Across the Cook Islands
- Rarotonga – The average rainfall in August is 152 mm / 6″
- Aitutaki – The average rainfall in August is 99 mm / 3.9″
- Mangaia – The average rainfall in August is 124 mm / 4.9″
- Mitiaro – The average rainfall in August is 96 mm / 3.8″
- Manihiki (North) – The average rainfall in August is 155 mm / 6.1″
- Penrhyn (North) – The average rainfall in August is 161 mm / 6.3″.
Tropical Storms in August
The South Pacific cyclone season starts in November and ends in April. As such, August is one of the best months to avoid tropical cyclones in the Cook Islands with a very low risk of tropical storms developing.
Best Places to Visit in the Cook Islands in August
Any part of the Cook Islands is stunning to visit during this warm, dry and pretty quiet time of the year. While we list all of the Cook Islands in What are the 15 Islands in the Cook Islands? for inspiration, a few places worth checking out in the Cook Islands during August include:
Rarotonga – Rarotonga is a hotspot for island holidays in the Cook Islands and for good reason. The largest island in the Cooks has high-quality tourism infrastructure, including resorts and various tours. It’s also the arrival island for international flights, making for an easy fly-and-flop getaway. Find out more about what Rarotonga is all about in the 50 Best Things to Do on Rarotonga.
Aitutaki – For similar reasons as visiting Rarotonga, Aitutaki is worth visiting in August for its developed tourist scene. However, Aitutaki is still much less visited than Rarotonga, effortlessly offering a tranquil South Seas getaway. Learn more about what to do in Aitutaki in the 20 Best Things to Do on Aitutaki.
Mauke – Escape the hustle and bustle of the Cook Islands’ busier islands and visit one of the lesser-visited paradises, Mauke. A tiki tour around the island will bring you to small beaches and photogenic coastal archways (formed by limestone, of course). But no visitor can miss out on a swim in the impressive Vai Tano Cave. Learn more about an island escape to Mauke in the 15 Best Things to Do in Mauke.
Again, any of the islands are decent to visit during August, so we recommend researching more on the subject using A Guide to the Best Islands of the Cook Islands.
August Packing List for Rarotonga and the Cook Islands
Be prepared for the Cook Islands in August by packing these few seasonal essentials:
- Light clothing layers for the day (cotton or linen preferably so it is super light)
- Light long-sleeved tops/jacket (to take the edge off those slightly cooler nights or to keep warm after boat trips)
- Light pants/trousers/skirt (to cover the knees when appropriate – church service or to protect from mosquitoes when hiking, for example)
- Closed walking shoes
- Sarong (pāreu – available on Rarotonga; it’s a good way to cover up when exploring the towns after swimming)
- Insect repellent
- High-factor sunscreen (that’s reef-safe and water-resistant).
Get more ideas on what to pack with our guide, What to Pack for Rarotonga & the Cook Islands: Cook Islands Packing List.
More About the Weather in Rarotonga and Cook Islands in August
That’s it for our complete guide to the weather and climate in Rarotonga and the Cook Islands in August. Check out the following articles for more weather advice:
- Rarotonga & the Cook Islands Weather, Seasons & Climate + Cook Islands Weather by Month
- The Best Time to Visit Rarotonga & the Cook Islands: A Month by Month Guide
- Rarotonga & the Cook Islands Weather in June
- Rarotonga & the Cook Islands Weather in July
- Rarotonga & the Cook Islands Weather in September
Finally, enjoy a comprehensive guide to planning a trip to the Cook Islands in The Best Cook Islands Travel Guide.