Climate and monthly weather forecast
Cook Islands

The Cook Islands, situated in the South Pacific Ocean, are an archipelago of 15 islands with a combined land area of just 240 square kilometres. The islands are scattered across 2.2 million square kilometres of ocean, placed neatly between French Polynesia to the east and Tonga to the west. A significant feature of the Cook Islands' geography is their isolation, lying in the heart of the South Pacific.

The Cook Islands' climate is classified as Tropical Rainforest under the Köppen climate classification, signifying no dry season and consistent warmth year-round. Throughout the year, the average monthly temperature hovers around 24°C (75.2°F), with a minimum mean temperature of at least 18°C (64.4°F). Rainfall is substantial, consistent, and evenly distributed across the year, typically exceeding 2000mm (78.74") annually. The islands experience more rain from November to April, which corresponds to the cyclone season in the South Pacific.

From May to October, the Cook Islands enjoy their 'dry' season. This period presents visitors with slightly cooler temperatures, usually ranging from 20°C (68°F) to 26°C (78.8°F), and reduced humidity compared to other months. During these months, the islands are less prone to cyclones, and rainfall is typically at its lowest. Visitors can engage in outdoor activities and sightseeing, benefiting from clear skies and comfortable temperatures. This period, therefore, represents the optimal time to visit the Cook Islands.

While the Cook Islands offer an appealing tropical climate year-round, the months between November and April are often less desirable for visitors. This period is the 'wet' season, with higher rainfall, increased humidity, and temperatures ranging from 22°C (71.6°F) to 30°C (86°F). Additionally, these months correspond with the South Pacific cyclone season, raising the risk of storms and cyclones. Although the islands are not frequently hit, the possibility of such weather events might disrupt travel plans.

The concept of spring is somewhat different in the Cook Islands due to its tropical climate, as the typical four seasons are not clearly distinguished. Nonetheless, the period from September to November could be regarded as spring, experiencing a gradual increase in temperature and rainfall. During this period, average temperatures vary from 22°C (71.6°F) to 28°C (82.4°F), and rainfall gradually increases, preparing for the incoming wet season.

Following the conventional Northern Hemisphere seasonal calendar, December through February would constitute summer in the Cook Islands. However, these months mark the beginning of the wet season, characterized by high temperatures, heavy rainfall, and increased humidity. Temperatures can soar to a high of 30°C (86°F) during these months, with rain often exceeding 200mm (7.87") per month. Despite the occasional rain showers, the islands continue to enjoy abundant sunshine.

The months of March to May, reflecting an autumn season, see the end of the wet season in the Cook Islands. During this transition phase, there is a gradual reduction in rainfall and a slight drop in temperature. Average temperatures usually range from 21°C (69.8°F) to 28°C (82.4°F) during this period. The end of the cyclone season also marks the return of stable weather, making it a good time for tourists to visit.

June to August signifies winter in the Cook Islands. This period is the driest and coolest time of the year, offering pleasant and comfortable weather. Average temperatures tend to range from 20°C (68°F) to 26°C (78.8°F). Rainfall during this period is at its lowest, generally falling below 100mm (3.94") per month. Despite being winter, the islands still enjoy a warm tropical climate with ample sunshine, proving to be an attractive destination for those looking to escape colder climates.

January marks the peak of the wet season in the Cook Islands, characterized by high temperatures, significant rainfall, and heightened humidity. This month is typically one of the warmest, with average temperatures ranging from 24°C (75.2°F) to 30°C (86°F). Weather in January »

February in the Cook Islands continues the trend established in January, as the warm, wet season persists. During this month, average temperatures remain consistently high, generally varying from 24°C (75.2°F) to 30°C (86°F). Weather in February »

March in the Cook Islands signifies the beginning of the transition from the wet to the dry season. This transition is marked by a gradual decrease in rainfall and a slight drop in temperatures compared to the preceding months. Average temperatures in March generally range from 23°C (73.4°F) to 29°C (84.2°F), offering warm conditions that remain pleasant for outdoor activities. The rainfall pattern observed in earlier months persists, with the southern islands experiencing higher precipitation levels than the northern group. Weather in March »

April in the Cook Islands marks a further progression in the shift from the wet to the dry season. Average temperatures during this month range from 22°C (71.6°F) to 28°C (82.4°F), a slightly cooler spectrum compared to the preceding months. Weather in April »

May in the Cook Islands is typically the start of the dry season, characterized by a decrease in rainfall and a further drop in temperatures. Average temperatures during this month range from 20°C (68°F) to 27°C (80.6°F), providing a comfortable climate for outdoor pursuits and exploration. Weather in May »

June in the Cook Islands is a period of stable, dry weather, as the dry season becomes firmly established. Average temperatures continue to decrease slightly, typically varying from 19°C (66.2°F) to 26°C (78.8°F), which are some of the coolest conditions observed throughout the year. Weather in June »

July in the Cook Islands is at the heart of the dry season, bringing forth the most consistent and stable weather patterns. Average temperatures during this month range from 18°C (64.4°F) to 25°C (77°F). These temperatures, some of the lowest of the year, coupled with decreased humidity, provide a comfortable climate for those wishing to explore the islands' natural beauty. Rainfall in July remains low, with the southern islands such as Rarotonga and Mangaia typically experiencing less than 100mm (3.94") of precipitation. Weather in July »

August continues the dry season in the Cook Islands, providing a predictable weather pattern characterized by low rainfall and relatively cool temperatures. During this month, average temperatures range from 18°C (64.4°F) to 25°C (77°F). Weather in August »

September in the Cook Islands marks the beginning of a gradual transition from the dry to the wet season. This period sees a slight increase in average temperatures, ranging between 19°C (66.2°F) to 26°C (78.8°F), and a subtle rise in humidity. Weather in September »

October in the Cook Islands marks a further progression in the transition from the dry to the wet season. During this month, average temperatures continue to rise, generally varying between 20°C (68°F) to 27°C (80.6°F). The increasing temperatures and a slow rise in humidity start to bring back the feel of the tropical climate that characterizes the wet season. Rainfall during October continues to increase compared to the preceding month. Weather in October »

November in the Cook Islands further advances the transition to the wet season. The weather during this month sees a further increase in both temperature and humidity. Average temperatures typically fluctuate between 22°C (71.6°F) to 28°C (82.4°F), providing warmer conditions that signify the onset of the wet season. Rainfall in November sees a substantial increase compared to the previous month. Weather in November »

December in the Cook Islands marks the official onset of the wet season, characterized by increased temperatures, high humidity, and substantial rainfall. Average temperatures during this month range from 23°C (73.4°F) to 29°C (84.2°F), signifying the return of the tropical warmth that defines this time of year. Rainfall in December is notably high. Weather in December »