Guam Island
September
Weather in Guam Island for September 2025
Your guide to Guam Island weather in September - trends and predictions
Until now, September 2025 in Guam Island has been nearly identical to the historical average, with a temperature of 28.9 °C (showing only a slight deviation of 0.3 °C).
The forecast for the next days in Guam Island predicts temperatures to be around 28 °C, close to the historical average.
In general, the average temperature in Guam Island at the beginning of September is 28.7 °C. As the month progressed, temperatures tended to moderately fall, reaching an average of 28 °C by the end of September.
Guam Island experiences heavy rainfall in September, with over 20 rainy days and an average total precipitation 715 mm.
Temperatures
Rain 🌧️
0
Dry days
30
Rainy days
0
Snow days
28°/26°
Temperatures
21 km/h
Avg max wind
81 %
Avg humidity
Guam Island Weather September
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Temperatures trend during September in Guam Island
See the weather trend as well as the moving average line
September weather in Guam Island day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. |  Patchy light rain with thunder | 29° /26° | 5.7 mm | 6 | |
| 2 Sept. |  Light rain shower | 29° /26° | 13.4 mm | 6 | |
| 3 Sept. | Light rain shower | 28° /25° | 14.1 mm | 6 | |
| 4 Sept. | Light rain shower | 29° /27° | 32.6 mm | 6 | |
| 5 Sept. | Light rain shower | 28° /26° | 7.9 mm | 6 | |
| 6 Sept. | Light rain shower | 29° /27° | 7.1 mm | 6 | |
| 7 Sept. | Patchy rain possible | 29° /27° | 2.5 mm | 6 | |
| 8 Sept. | Patchy rain possible | 29° /27° | 5.3 mm | 6 | |
| 9 Sept. |  Moderate or heavy rain shower | 29° /26° | 10.6 mm | 6 | |
| 10 Sept. | Moderate or heavy rain shower | 28° /26° | 26.3 mm | 6 | |
| 11 Sept. | Moderate or heavy rain shower | 28° /26° | 64.1 mm | 6 | |
| 12 Sept. | Moderate or heavy rain shower | 28° /26° | 25.5 mm | 6 | |
| 13 Sept. | Moderate or heavy rain shower | 28° /25° | 22.6 mm | 6 | |
| 14 Sept. | Moderate or heavy rain shower | 29° /25° | 31.2 mm | 6 | |
| 15 Sept. | Moderate or heavy rain shower | 27° /25° | 49.7 mm | 6 | |
| 16 Sept. |  Heavy rain | 29° /26° | 20.5 mm | 2 | |
| 17 Sept. | Heavy rain | 27° /25° | 30.2 mm | 0.3 | |
| 18 Sept. |  Moderate rain | 29° /26° | 12.7 mm | 2.7 | |
| 19 Sept. | Moderate rain | 29° /27° | 10 mm | 3.2 | |
| 20 Sept. | Patchy rain possible | 30° /27° | 4.1 mm | 6 | |
| 21 Sept. | Patchy rain possible | 29° /27° | 3.7 mm | 6 | |
| 22 Sept. | Moderate rain | 28° /25° | 9.6 mm | 6 | |
| 23 Sept. | Moderate rain | 28° /24° | 11.7 mm | 6 | |
| 24 Sept. | Moderate rain | 27° /26° | 7.2 mm | 6 | |
| 25 Sept. | Patchy rain possible | 29° /25° | 4.3 mm | 6 | |
| 26 Sept. | Patchy rain possible | 28° /26° | 3 mm | 6 | |
| 27 Sept. | Moderate rain | 28° /27° | 12.5 mm | 6 | |
| 28 Sept. | Moderate rain | 27° /25° | 12.5 mm | 6 | |
| 29 Sept. | Patchy rain possible | 28° /26° | 1.8 mm | 6 | |
| 30 Sept. | Light rain shower | 29° /28° | 1.6 mm | 6 | |
| Next | |||||
Important Notice
Our weather forecast for Guam Island in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Guam Island forecast closer to your planned date for the most up-to-date weather information.
Change Month
Guam Island in September - FAQ
What are the expected maximum and minimum temperatures in Guam Island during September?
During September, expect a variety of temperatures with highs around 28° and lows near 26°, suitable for diverse activities and preferences.
How much rainfall should be expected in Guam Island during September?
Significant rainfall exceeding 715 mm is expected in Guam Island during September, occurring over more than 30 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Guam Island during September?
The average wind speed in Guam Island during September is 21 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Guam Island
Explore the daily rainfall trends and prepare for Guam Islands September weather 💧
UV exposure in Guam Island during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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