Guam weather in September

Monthly temperatures, rain, humidity, what to wear and what to pack — 2024–2025 historical average

Guam September weather at a glance

D Challenging 😓

In September, Guam averages 27.2°C, with typical highs of 30.4°C and lows of 24.9°C. The historical average is 29 wet days and 84% humidity.

Compared with Seoul in September, it is 4.3°C warmer than Seoul, with 16 more wet days.

Guam September temperature & humidity

Average27.2°CHigh 30.4° / low 24.9°

Humidity84%

Wet days29 days95% of days

Day–night range5.5°

Guam September rain & wet days

Wet days29 daysHistorical monthly average

Share of wet days95%Not a forecast probability

Pack a light rain jacket, waterproof pouch and quick-dry shoes. Keep an indoor stop available between outdoor activities.

What to wear in Guam in September

Expect intense heat. Pack lightweight quick-dry clothing, sun protection and a refillable bottle. Rain is frequent at roughly 29 days in the month; pack a rain jacket and water-resistant shoes. High humidity makes quick-dry clothing and a spare top especially useful.

DaytimeBreathable short sleeves, hat and sunscreen · average high 30.4°C
Morning & eveningLight layer for air-conditioned rooms · average low 24.9°C
FootwearComfortable walking shoes; quick-dry footwear for rainy days.

Useful extras

Quick-dry clothingPortable fanRefillable water bottleRain jacketWater-resistant shoesCompact umbrellaSpare quick-dry top

Choose a destination packing checklist →

Packing essentials

Coupang affiliate links · We earn a commission on purchases. Products are sold on the Korean Coupang store.

Travel compression packing pouches
코멧 여행용 압축 파우치 4종 세트 Travel plug adapter
에너자이저 PD 45W 여행용 멀티 어댑터, 화이트 Portable fan
홈플래닛 컴팩트 BLDC 휴대용 선풍기 GXZ-F78 Compact folding umbrella
솔리앤 초경량 UV차단 3단 자동우산 Inflatable travel neck pillow
마이워니 여행용 에어 목베개

Guam September sunrise & sunset times

2026 September · Local time (Pacific/Guam)

Sunrise on the 15th06:10

Sunset on the 15th18:22

Daylight duration12h 13m

Start, middle and end of the month
Date	Sunrise	Sunset	Daylight
2026-09-01	06:10	18:32	12h 23m
2026-09-15	06:10	18:22	12h 13m
2026-09-30	06:10	18:12	12h 1m

For sunset photos, arrive before the listed sunset time. Clouds, mountains and buildings can change when the sun becomes visible or disappears.

Calculated for the city coordinates with daylight saving applied. SunCalc · tz-lookup

Guam travel updates

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Guam travel essentials

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Best months to visit Guam

Bar height shows our simple weather-comfort score, not a safety rating; colour shows temperature.

J F M A M J J A S O N D

ColdHot

September weather by year

September 202427°27 wet days, 87% humidity

September 202527.4°30 wet days, 81% humidity

Daily weather in 2025

Daily high and low temperatures; blue labels show precipitation

132°26°4.2mm

231°25°8.5mm

331°25°19mm

430°25°17mm

530°25°20mm

631°26°11mm

732°26°11mm

831°25°8.7mm

931°25°13mm

1031°25°5.4mm

1132°25°15mm

1232°25°16mm

1331°24°18mm

1431°25°6.2mm

1530°25°15mm

1629°25°17mm

1731°25°11mm

1831°25°11mm

1929°25°26mm

2033°25°11mm

2131°25°4.8mm

2232°25°21mm

2330°25°7.6mm

2432°25°6.4mm

2532°25°9.5mm

2631°24°2.3mm

2731°24°12mm

2830°25°20mm

2930°25°14mm

3031°25°1.6mm

Frequently asked questions

What is Guam weather like in September?

In September, Guam averages 27.2°C, with typical highs of 30.4°C and lows of 24.9°C. The historical average is 29 wet days and 84% humidity. Our weather-comfort rating for this month is challenging.

Does it rain a lot in Guam in September?

There are about 29 wet days in September. Pack a rain jacket and water-resistant shoes.

What should I wear in Guam in September?

What are the best months to visit Guam?

No months meet the A or B threshold in our temperature-and-precipitation score. Compare the monthly values with your planned activities.

Where can I check Guam weather in September in real time?

Check local webcams for the view right now and a local weather service for today’s forecast. Monthly temperatures here are historical averages.

What time are sunrise and sunset in Guam in September?

On 2026-09-15, calculated sunrise is 06:10 and sunset is 18:22 in local time (Pacific/Guam). Times vary by date and terrain.

Guam weather by month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

More Americas destinations in September

Los Angeles San Francisco Las Vegas Seattle Chicago Boston Washington DC Miami Orlando Hawaii Honolulu Saipan Vancouver Toronto Banff Montreal Mexico City Cancun Lima All destinations →

Open-Meteo (CC BY 4.0) · 2024–2025 historical data, aggregated and rounded by this site. Not a forecast or long-term climate normal. Calculation method and limitations