Climate and monthly weather forecast
American Samoa, USA

American Samoa experiences a tropical climate (Köppen classification Aw) with hot, wet summers and warm, dry winters. The climate is characteristically hot, humid, and wet, with sunny days throughout the year. American Samoa is an unincorporated territory of the United States that lies to the southeast of Samoa in the South Pacific Ocean. Low latitudes and engulfment by the Pacific Ocean chiefly influence the climate of the islands.

American Samoa, nicknamed Motu o Fiafiaga or the Islands of Paradise, consists of five rocky, volcanic islands and two coral atolls. Lata Mountain has the highest elevation at 970 meters above sea level. The islands are home to the highest sea cliffs in the world at 910 meters. Remarkable coastal reef ecologies and rainforests give the islands the highest marine biodiversity in the United States. The volcanic islands of Tutuila, Ofu, Olosega, and Ta'u receive between 120" (3048mm) along the coasts to 200" (5080mm) in the hilly regions and are wetter than the small islands. Aunu'u, along with Swains and Rose atolls, receives up to 100" (2540mm) of rainfall.

The best time to visit American Samoa is in the short and relatively dry winter season from June to September. The coldest period of the year sees a drastic rise in tourist population with a vast coastline, abundant public beaches, and a diverse landscape in the backdrop of mountains. The days are sunny and bright even at the peak of the winter, while the nights are comfortable. The season is perfect for romantic getaways, water adventures, and family vacations. However, do not expect entirely dry days as rain is omnipresent in American Samoa.

The worst time to visit American Samoa is from December to March when the rainfall is the heaviest in the year. Thunderstorms are frequent, and the rainfall is intense, although for short periods. The long summer season is at its peak, and temperatures climb to 90°F (32.2°C) along with a stifling rise in humidity. Tropical cyclones of the South Pacific are frequent between late December and March but occasionally occur in November and stretch up to May. A good reason for budget travelers to consider the slack season is the significant reduction in flight and accommodation costs.

Spring, stretching from September to November, is a transitional period in American Samoa. During these months, temperatures generally hover from 75°F (23.9°C) to 88°F (31.1°C). Rainfall begins to intensify as the islands transition from the dry to the wet season, with occasional showers becoming more frequent. Humidity levels start to rise, though they remain bearable for most. The trade winds continue to bring clouds and sporadic rainfall, setting the stage for the upcoming wet season.

Summer in American Samoa, from December to February, is characterized by its wet conditions. Rainfall is at its peak, and temperatures oscillate between 77°F (25°C) and 90°F (32.2°C). As mentioned earlier, this period also sees an increase in humidity, making the days feel hotter than they actually are. Though thunderstorms are frequent, they tend to be short-lived. Despite the wet conditions, the islands' marine biodiversity can be appreciated during underwater excursions.

March to May marks the autumn season in American Samoa. During this time, the weather begins to show signs of drying, although heavy rainfall is still common. The temperatures remain warm, ranging from 74°F (23.3°C) to 88°F (31.1°C). As the islands inch towards the dry season, the frequency of rainfall gradually decreases. This period also witnesses diminishing cyclone risks, making it relatively safer for travel.

June through August is winter in American Samoa. The climate is drier and slightly cooler during these months, with temperatures fluctuating between 70°F (21.1°C) and 85°F (29.4°C). While rainfall is less compared to the wet season, occasional showers are still common, especially due to the southeast trade winds. This season is characterized by its pleasant weather, with a comfortable combination of warmth, reduced rainfall, and moderate humidity levels, offering an inviting atmosphere for visitors.

January is situated right in the heart of summer for American Samoa and is characteristic of the wet season that the islands experience during this time. As one of the wettest months, January witnesses frequent, albeit brief, thunderstorms. Weather in January »

February, like January, is in the midst of American Samoa's summer and consequently remains entrenched in the wet season. This month often sees consistent rainfall patterns, with occasional, though transient, thunderstorms adding to the area's precipitation levels. Weather in February »

March marks a transitional phase for American Samoa's climate as it nears the tail end of the wet season. Rainfall persists during this month, though it generally starts showing a downward trend as the islands move towards the drier part of the year. Weather in March »

April stands at the cusp of the climatic shift in American Samoa, representing the final vestiges of the wet season and heralding the onset of drier months. The temperatures in April consistently range from 78°F (25.6°C) to 88°F (31.1°C), upholding the tropical warmth the islands are renowned for. Weather in April »

May ushers in a notable shift in American Samoa's climate. As the islands transition more deeply into the dry season, the reduction in rainfall becomes more pronounced. Temperatures during May remain comfortably tropical, typically ranging from 78°F (25.6°C) to 87°F (30.6°C). Weather in May »

June firmly establishes itself in the heart of the dry season for American Samoa. Rainfall continues its decline from the previous months, making way for clearer skies and more consistent sunny days. Temperature patterns remain fairly stable, usually spanning from 78°F (25.6°C) to 86°F (30°C). Weather in June »

In the midst of the southern hemisphere's winter, July in American Samoa is characterized by its relatively dry and temperate conditions. The temperatures, though slightly cooler compared to the earlier months, comfortably oscillate between 77°F (25°C) and 85°F (29.4°C). Weather in July »

As August unfolds in American Samoa, the dry season continues its reign. This month remains one of the least rainy periods of the year, further solidifying the patterns observed in the preceding months of the dry season. Temperatures, in keeping with the prevailing trends of the southern hemisphere's winter, fluctuate between 77°F (25°C) and 84°F (28.9°C). Weather in August »

September in American Samoa signals the culmination of the dry season and the gradual shift towards the onset of the wetter months. Despite the transition, the month largely retains the drier conditions, with temperatures averaging between 78°F (25.6°C) and 85°F (29.4°C). Weather in September »

October in American Samoa marks a noticeable shift from the receding dry season towards the onset of the wetter months. This change heralds an increase in humidity and a rise in rainfall frequency. The month experiences temperatures that typically range from 79°F (26.1°C) to 86°F (30°C), with the latter half being more inclined towards wetter conditions. Progressing from September to October, there's a more pronounced increment in rainfall. Weather in October »

November in American Samoa ushers in the heart of the wet season, bringing with it increased rainfall and heightened humidity levels. Temperatures during this month maintain a tropical warmth, hovering from 80°F (26.7°C) to 87°F (30.6°C). Weather in November »

December firmly situates American Samoa within the wet season, characterized by a surge in humidity and regular tropical downpours. The month witnesses temperatures predominantly varying from 81°F (27.2°C) to 88°F (31.1°C). Weather in December »