September is an excellent time to visit the Cook Islands despite the cooler temperatures. You can expect mild, balmy weather, mainly clear, sunny skies with little or no rainfall and cool evenings.
The comfortable mild weather is ideal for a range of outdoor activities, including snorkelling, scuba diving and spotting humpback whales during their migration to the Cook Islands.
How hot is it in the Cook Islands in September?
Daytime temperatures average a high of 25°C (77°F) in the Cook Islands in September, with low heat and humidity, falling to a night-time low of 20°C (68°F).
How sunny is it in the Cook Islands in September?
There are normally six hours of sunshine each day in the Cook Islands in September – that's around 50% of daylight hours.
Sunrise & sunset in September?
Sunrise is around 6:35am with sunset around 6:35pm.
How warm is the sea in the Cook Islands in September?
The average sea temperature in the Cook Islands in September is 24°C (75°F), which is still pleasant for swimming.
Does it rain in the Cook Islands in September?
Monthly rainfall in the Cook Islands in September averages 62mm (2in), distributed across six days on average.
How windy is it in the Cook Islands in September?
September sees an average wind speed of around 23 kilometres per hour (14 mph; 12 knots). The predominant average wind direction in the Cook Islands is from the east.
What to do in the Cook Islands in September?
September offers a good combination of weather for a range of water sports, including swimming, scuba diving, snorkelling and kitesurfing.
The mild temperature is also good for hiking and exploring the islands.
September falls in the middle of the whale watching season.
None. While September falls within the shoulder season, it’s still a good idea to book accommodation and flights early.
|High Temp: 25°C (77°F)|
|Low Temp: 20°C (68°F)|
|Sunshine: 6 hours per day|
|Daylight: 12 hours per day|
|Wet Days: 6 days with some rain|
|Rainfall: 62mm (2in) per month|
|Comfort Level: Low heat & 80% humidity|
|UV Index: High|
|Wind speed: 23 km/h (14 mph; 12 knots)|
|Sea Temp: 24°C (75°F)|
|Avarua, Rarotonga, Cook Islands|
The best time of year to visit the Cook Islands is during the winter dry season from June through September.
For warmer weather visit in April and May, or in October and November when you can expect higher temperatures but also the probability of more rain showers.
Note: Meteorological data for the Cook Islands is based on weather statistics gathered for the 30-year period 1991 to 2020, and is sourced from the Cook Islands Meteorological Service at the closest weather station, Rarotonga International Airport (RAR), located less than 3km (2mi) west of Avarua Harbour. Additional climate data is sourced from the World Meteorological Organization (WMO).
Advice on the best time to visit a particular destination is based on average local weather statistics, when the weather conditions are generally better than at other times of the year. We consider high and low temperatures, risk of rain (and thunderstorms, etc.), amount of sunshine and sea temperature. For general outdoor activities we favour clear, rainless days with a temperature range between 18°C (64°F) and 27°C (80°F); and for hot-weather activities we favour clear, rainless days with a temperature range between 24°C (75°F) and 32°C (89°F). Often, the best times to visit correspond to high season and therefore involve higher prices.
Latest update: Cook Islands weather in September: 24 October, 2023
Disclaimer: The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data and conditions at any given location and time are unpredictable and variable. We assume no responsibility and can not be held legally responsible for any decisions made on the basis of the information presented on this site.