United States (Guam) Guam Weather in September — Climate Guide
September in Guam is high
September is high for Guam.
Typhoon peak. Hotels reasonable. Korean Chuseok shoulder.
Travel score
Guam September Weather Stats
Avg High
30°C
Avg Low
25°C
Rainy Days
17
250mm total
Sunshine
6h
Daily avg
Humidity
80%
high
UV Index
11
Extreme
Wind
18 km/h
Gusts 40
Sea Temp
29°C
perfect
Crowds
Busy
At attractions
September Sunrise & Sunset
Air Quality
PM2.5
10 μg/m³
PM10
20 μg/m³
Status
good
Feels-Like Temperature & Wind
Feels like
Daytime
34°C
Nighttime
26°C
Humidity and wind affect how the actual temperature feels.
Wind
18 km/h
Max gust 40 km/h
Activities Recommended for September
September Travel Pros & Cons
Pros
- Hotels reasonable
- Korean Chuseok
Cons
- Typhoon peak
- Rainy 17 days
September Events & Festivals
- Korean Chuseok shoulder
- Typhoon peak
Guam in September — Full Picture
Typhoon peak. Hotels reasonable. Korean Chuseok shoulder.
What to Wear & What to Pack
Hot tropical + typhoon.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
29.7°C
24.3°C
9/mo
Summer (Jun·Jul·Aug)
30°C
25°C
15/mo
Autumn (Sep·Oct·Nov)
Current29.7°C
25°C
15.7/mo
Winter (Dec·Jan·Feb)
28°C
23.3°C
10.3/mo
Guam Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| January (Best) | 28° | 23° | 10d·130mm | 7h | 78% | 11 | Very busy | Peak |
| February (Best) | 28° | 23° | 9d·100mm | 7h | 76% | 11 | Very busy | Peak |
| March (Best) | 29° | 24° | 8d·80mm | 8h | 76% | 12 | Very busy | Peak |
| April (Best) | 30° | 24° | 8d·90mm | 9h | 76% | 12 | Busy | Peak |
| May (Best) | 30° | 25° | 11d·130mm | 8h | 77% | 12 | Very busy | Peak |
| 30° | 25° | 13d·145mm | 7h | 78% | 12 | Busy | Shoulder | |
| 30° | 25° | 15d·200mm | 7h | 79% | 11 | Very busy | Peak | |
| 30° | 25° | 17d·230mm | 6h | 80% | 11 | Very busy | Peak | |
| 30° | 25° | 17d·250mm | 6h | 80% | 11 | Busy | Shoulder | |
| 30° | 25° | 16d·230mm | 7h | 79% | 11 | Busy | Shoulder | |
| November (Best) | 29° | 25° | 14d·175mm | 7h | 78% | 11 | Busy | Shoulder |
| December (Best) | 28° | 24° | 12d·130mm | 7h | 78% | 10 | Very busy | Peak |
View Other Months
Guam September Hotel Picks
Frequently Asked Questions
Is September a good time to visit Guam?
Guam in September is high. Tourist crowds are busy and flight/hotel prices are shoulder.
What's the average temperature in Guam in September?
Guam September averages a high of 30°C and a low of 25°C.
Does it rain much in Guam in September?
Guam September averages 250mm of rainfall over about 17 rainy days.
What should I wear in Guam in September?
Hot tropical + typhoon.
What time are sunrise and sunset in Guam in September?
Guam September sunrise is 06:25 and sunset is 18:20, with 11h 55min of daylight.
What's the air quality like in Guam in September?
Guam September air quality (AQI) averages 30, rated Good. PM2.5 averages 10μg/m³.
What activities are recommended in Guam in September?
In September, Guam is great for Tumon Bay morning, Indoor cultural, Korean BBQ.
Is September peak season in Guam?
Guam September crowds are busy and prices are shoulder. Advance reservations are strongly recommended.
Best Months to Visit Guam
View Other Months
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.