American Samoa Weather, Seasons & Climate + Weather by Month

American Samoa Average Monthly Weather Data

American Samoa enjoys warm, tropical temperatures year-round due to its location just south of the Equator. There's very little variation in both air and sea temperatures throughout the year, with tradewinds during the dry season having a more cooling effect than the actual temperature itself.

The hottest months are typically from December to April, when daytime highs average around 86°F (30°C), while the coolest period is from June to September, with average highs still a pleasant 82–84°F (28–29°C). Nighttime lows remain fairly consistent, averaging around 75°F (24°C) year-round.

American Samoa Year-Round Temperature: What Is the Average Temperature in American Samoa?

The average maximum temperature in American Samoa is 84°F (29°C), while the average minimum is around 75°F (24°C). The average temperature in American Samoa hovers around 80°F (27°C) year-round.

Scroll down for temperature listings for each month in American Samoa.

The Sea Temperature in American Samoa

Like its air temperature, the sea temperature in American Samoa stays reliably warm throughout the year.

With its year-round tropical climate, the ocean is always inviting for swimming, snorkelling and water sports. The average annual sea temperature hovers around 83°F (29°C), offering perfect conditions for enjoying the South Pacific.

The warmest water temperatures are typically felt during the wet season, with the average sitting at 84°F (29°C) from November to April.

Even during the dry season between May and October, the sea remains pleasant, with average temperatures only dipping slightly to around 82°F (28°C).

Scroll down to see monthly sea temperatures in American Samoa in our detailed weather guides.

Don't be too swayed by the labels "dry" and "wet" season; rainfall in American Samoa is possible throughout the year. The islands receive an average of around 114 in (2,897 mm) of rain annually, with rain falling on approximately 113 days of the year.

As expected, the wet season (November to April) brings the heaviest rainfall, averaging between 10 to 16 in (250 to 395 mm) per month. This is also when tropical downpours and storm activity are most frequent.

During the dry season (May to October), American Samoa still sees occasional rain, with monthly rainfall ranging from 5 to 9 in (125 to 233 mm). Whilst this period is drier and more settled, short showers, often heavy, can still roll in, especially in the evenings or early mornings.

Thanks to the island's lush, volcanic terrain, inland areas tend to get more rain than the coastal zones. Regional microclimates also mean that if it's raining in one village, it might be sunny just a few miles away.

American Samoa enjoys long daylight hours throughout the year, with around 13 hours of daylight daily from November to February. During the dry season (May to October), daylight drops slightly to about 11 to 12 hours, with June having the shortest days.

Sunshine-wise, the sunniest months are typically from August to October, when the islands see an average of 5-6 hours of bright sunshine per day. Meanwhile, December and January are usually the cloudiest months, with only about 5 hours of sunshine on average.

American Samoa, located in the South Pacific cyclone belt, is at risk of tropical cyclones (hurricanes) during the wet season from November to April. The highest risk months are December, January and February, with an increased chance of activity during El Niño years.

The territory has experienced several major cyclones. Cyclone Val (1991) severely impacted the islands, causing widespread destruction to homes, schools and infrastructure. Cyclone Heta (2004) brought storm surges and power outages, whilst Cyclone Gita (2018) left significant flooding and property damage in its wake.

Whilst severe cyclones/hurricanes are relatively rare, American Samoa has well-established emergency response plans in place. For peace of mind, check forecasts regularly and read our Cyclone Safety in American Samoa guide to stay prepared during cyclone season.

The year kicks off hot, humid and wet in American Samoa, right in the middle of the wet and cyclone season. Expect frequent showers and high humidity. It’s also the hurricane season in the South Pacific, so be aware of cyclone warnings – see our cyclone guide for more details. Otherwise, the country is vibrant with New Year celebrations, as one of the last places on Earth to welcome the New Year.

Average temperature: 86°F (30°C) in the day, 75°F (24°C) at night
Average sea temperature: 84°F (29°C)
Average rainfall: 15.5 in (394 mm)
Daylight hours: 13 hours

For more in-depth information, see our complete guide to American Samoa Weather in January.

February remains sizzling and humid, with regular, intense afternoon showers. On a positive note, the month is much calmer in terms of tradewinds, making it the best time to snorkel, scuba dive, head out on a fishing trip, kayak and whatever you want to do on the water.

It’s still cyclone/hurricane season, however, so stay alert for storm updates. The lush green landscape and virtually no tourists make it a peaceful, verdant time to explore hidden waterfalls and rainforest paths.

Average temperature: 86°F (30°C) in the day, 75°F (24°C) at night
Average sea temperature: 84°F (29°C)
Average rainfall: 12 in (308 mm)
Daylight hours: 13 hours

For more in-depth information, see our complete guide to American Samoa Weather in February.

March offers more of the same tropical warmth and humidity, although rainfall may slightly ease compared to earlier months. It’s still wet but transitioning, but the calmer winds compared to the dry season make March an excellent time to get out on the water.

What's more, you’ll find fewer crowds, making it ideal for hitting the historical sites, national park trails and waterfalls without others getting in the way of your photos.

Average temperature: 86°F (30°C) in the day, 75°F (24°C) at night
Average sea temperature: 84°F (29°C)
Average rainfall: 12.6 in (319 mm)
Daylight hours: 12 hours

For more in-depth information, see the complete guide to American Samoa Weather in March.

April marks the tail end of the wet season. Showers become less frequent and sunshine increases, although humidity remains high. It's your last chance to book into a less tumultuous fishing or scuba diving charter before the tradewinds start to pick up.

All in all, the island feels fresh and vibrant, perfect for early morning treks or secluded beach visits before the drier season arrives.

Average temperature: 86°F (30°C) in the day, 75°F (24°C) at night
Average sea temperature: 84°F (29°C)
Average rainfall: 9.8 in (249 mm)
Daylight hours: 12 hours

For more in-depth information, see our full guide to American Samoa Weather in April.

May ushers in the dry season. Rainfall begins dropping, the heat remains pleasant, and humidity starts to ease. It's also the start of the tradewind season, so time your beach activities in the morning or low-to-mid tide for a more pleasant experience.

In short, it's a comfortable time to enjoy outdoor activities like the national park trails, cultural tours and exploring beaches.

Average temperature: 84.2°F (29°C) in the day, 75°F (24°C) at night
Average sea temperature: 84°F (29°C)
Average rainfall: 7.8 in (198 mm)
Daylight hours: 11 hours

For more in-depth information, see our complete guide to American Samoa Weather in May.

June ranks as one of the driest months of the year, making it absolutely perfect for outdoor exploration; we're talking verdant rainforest hikes and checking out eerie WW2 relics. Beach days are nothing short of magical, as you can count on rain being a rare occurrence during this delightful month.

It also happens to be the most popular time for visitors to check out America's final frontier, so while this doesn't mean it's crowded, you're more likely to bump into fellow travellers to share your experiences with.

Average temperature: 84°F (29°C) in the day, 73.4°F (23°C) at night
Average sea temperature: 82°F (28°C)
Average rainfall: 6.3 in (159 mm)
Daylight hours: 11 hours

For more in-depth information, see the complete guide to American Samoa Weather in June.

In July, dry-season bliss continues. Expect daily sunshine and minimal showers, except when Mt Pioa reminds us why we call it "Rainmaker Mountain". Balmy days and warm seas make it ideal for water-based fun, although tradewinds can dampen the fun with choppy waves. Needless to say, UV protection is still recommended during prolonged outdoor adventures.

Average temperature: 84°F (29°C) in the day, 73°F (23°C) at night
Average sea temperature: 82°F (28°C)
Average rainfall: 5 in (125 mm)
Daylight hours: 11 hours

For more in-depth information, see the complete guide to American Samoa Weather in July.

August remains dry, sunny and pleasantly warm with the lowest humidity of the year. The tradewinds keep you pleasantly cool for exploring historical landmarks and tackling the national park trails. However, this makes it a little challenging for water activities, especially for boat excursions. For snorkelling and swimming from shore, aim for morning or low-to-mid tide for typically calmer conditions.

Note that August is also a slightly busier season for tourism, so you may also want to book accommodation well in advance.

Average temperature: 82°F (28°C) in the day, 73°F (23°C) at night
Average sea temperature: 81°F (27°C)
Average rainfall: 6 in (146 mm)
Daylight hours: 12 hours

For more in-depth information, see the complete guide to American Samoa Weather in August.

September maintains the dry-season calm: mild humidity, little rain and steady sunshine with cooling coastal breezes. Although the already quiet tourist season is starting to slow, the local school holidays pick up, meaning that you could be sharing attractions with friendly locals.

Average temperature: 84°F (29°C) in the day, 73°F (23°C) at night
Average sea temperature: 82°F (28°C)
Average rainfall: 7 in (175 mm)
Daylight hours: 12 hours

For more in-depth information, see the complete guide to American Samoa Weather in September.

October signals the end of the dry season. Brief, tropical showers may appear, often in the afternoon. Temperatures stay warm and humidity rises slightly. Still, it's a great time to visit, with very few tourists yet events to enjoy, like the Alega Tattoo Festival and the opportunity to spot humpback whales.

Average temperature: 84°F (29°C) in the day, 73°F (23°C) at night
Average sea temperature: 82°F (28°C)
Average rainfall: 9.2 in (233 mm)
Daylight hours: 12 hours

For more in-depth information, see the complete guide to American Samoa Weather in October.

November marks the start of the wet season and relief from tradewinds. Rainfall increases and humidity intensifies, but the surrounding waters typically calm for better snorkelling and boat trips. On land, the lush jungle comes alive, but you may encounter sudden showers. It’s also a good time to be aware of hurricane alerts and monitor forecasts closely.

Average temperature: 86°F (30°C) in the day, 75°F (24°C) at night
Average sea temperature: 82°F (28°C)
Average rainfall: 10 in (252 mm)
Daylight hours: 13 hours

For more in-depth information, see the complete guide to American Samoa Weather in November.

December is wet, humid and increasingly prone to tropical storms as the wetter months continue. Despite the rain, festive holiday activities carry on with Christmas celebrations, church events and a strong community atmosphere—so the tropical “Christmas spirit” is very much alive. Also, be aware that the holiday season is a busy time to fly to American Samoa, so make your bookings well in advance.

Average temperature: 86°F (30°C) in the day, 75°F (24°C) at night
Average sea temperature: 84°F (29°C)
Average rainfall: 13.4 in (341 mm)
Daylight hours: 13 hours

For more in-depth information, see the complete guide to American Samoa Weather in December.

Now that you know about the weather patterns in American Samoa, here are the answers to the internet's frequently asked questions about American Samoa's climate and weather conditions!

What is the best time to visit American Samoa weather-wise?

The best time to visit American Samoa is during the dry season from May to October when you'll experience less rainfall and more comfortable humidity levels. Temperatures remain consistently warm year-round, averaging 82-86°F (28-30°C).

Does American Samoa have a hurricane season?

Yes, American Samoa's cyclone season runs from November to April, with the highest risk typically occurring between December and March. However, direct hits are relatively rare due to the islands' location. For more information, check out Cyclone Safety in American Samoa.

Is American Samoa humid all year round?

Yes, American Samoa maintains high humidity levels throughout the year, typically ranging from 75-85%. The trade winds help provide some relief, particularly during the dry season months.

What should I pack for American Samoa's weather?

Pack lightweight, breathable clothing, a reliable rain jacket, sun protection, and quick-dry fabrics. Don't forget waterproof bags for your electronics during the rainy season. For more information, check out What to Pack for American Samoa: American Samoa Packing List.

Which month has the most rain in American Samoa?

In terms of rainfall, January is usually the wettest month in American Samoa with 15.5 in (394 mm) on average. There are normally 18 days in January with some rain.