Guam Weather
A month-by-month look at temperature, rainfall and what to pack in Guam. The annual average is 29°C high / 24°C low — hottest in April (30°C) and coldest in January (23°C).
Guam Weather at a Glance
As of 2026A quick summary of Guam's year-round climate and the best time to visit.
- Annual average
- 29° / 24°
- Best time to visit
- January, February, March
- Hottest month
- April (30°C)
- Coldest month
- January (23°C)
- Wettest month
- September (250mm)
- Driest month
- March (80mm)
As of 2026, Guam's weather averages 29°C high / 24°C low across the year, and the best time to visit for stable temperatures, rainfall and crowds is January, February, March. The hottest month is April (30°C), the coldest is January (23°C), and the wettest is September (250mm).
Best Time to Visit Guam
Guam Weather Month by Month
Tap any month for a detailed guide with what to wear, sunrise/sunset and air quality.
| Month | High/Low | Rain | Rainy days | Crowds | |
|---|---|---|---|---|---|
| January | 28° / 23° | 130mm | 10 | Very busy | Details → |
| February | 28° / 23° | 100mm | 9 | Very busy | Details → |
| March | 29° / 24° | 80mm | 8 | Very busy | Details → |
| April | 30° / 24° | 90mm | 8 | Busy | Details → |
| May | 30° / 25° | 130mm | 11 | Very busy | Details → |
| June | 30° / 25° | 145mm | 13 | Busy | Details → |
| July | 30° / 25° | 200mm | 15 | Very busy | Details → |
| August | 30° / 25° | 230mm | 17 | Very busy | Details → |
| September | 30° / 25° | 250mm | 17 | Busy | Details → |
| October | 30° / 25° | 230mm | 16 | Busy | Details → |
| November | 29° / 25° | 175mm | 14 | Busy | Details → |
| December | 28° / 24° | 130mm | 12 | Very busy | Details → |
What to Wear in Guam by Season
Warm tropical.
Hot tropical + rain.
Hot tropical + rain.
Tropical dry.
Guam Weather FAQ
What is the best time to visit Guam? +
For weather, January, February, March are the most comfortable months. Highs sit around 28°C with relatively stable rainfall and crowds.
What are the hottest and coldest months in Guam? +
The hottest month is April with an average high of 30°C, and the coldest is January with an average low of 23°C. The annual average is 29°C high / 24°C low.
When does it rain most in Guam? +
The wettest month is September (250mm over about 17 rainy days) and the driest is March (80mm). Total annual rainfall is roughly 1890mm.
What should I pack for Guam? +
Spring (Mar–May) averages 30/24°C — Warm tropical. Summer (Jun–Aug) averages 30/25°C — Hot tropical + rain. Autumn (Sep–Nov) averages 30/25°C — Hot tropical + rain. Winter (Dec–Feb) averages 28/23°C — Tropical dry.
What is the weather in Guam this month (June)? +
June averages 30°C high / 25°C low with 145mm rainfall over about 13 rainy days. Crowds are busy and prices are moderate.
Keep Planning Your Guam Trip
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.