Guam Weather Forecast
Guam weather: 89°F, overcast. Hourly forecast, 14-day outlook, UV, air quality and the best time to visit.
Risk assessment for Guam
Derived from the current forecast window - not an official warning.
Peak gusts of 41 mph and 5 thunderstorm days in the next 16 days.
Wettest single day forecast at 1,1 in, 9,7 in across the window. Flash flooding risk rises sharply above 50 mm in a day.
Active alerts for Guam
Derived from the forecast. No official alert feed is wired for this country yet.
16-day forecast for Guam
Daily highs and lows, precipitation and UV.
| Day | Conditions | High / Low | Precip | Wind | UV |
|---|---|---|---|---|---|
| Tue, Aug 25 | 🌦️ Light showers | 90° / 79° | 94% · 0,2 in | 13 mph | 8 |
| Wed, Aug 26 | ⛈️ Thunderstorm | 87° / 77° | 95% · 0,6 in | 9 mph | 8 |
| Thu, Aug 27 | 🌦️ Light showers | 90° / 77° | 92% · 0,4 in | 10 mph | 9 |
| Fri, Aug 28 | 🌧️ Showers | 88° / 77° | 80% · 0,4 in | 12 mph | 8 |
| Sat, Aug 29 | ⛈️ Thunderstorm | 89° / 77° | 87% · 0,7 in | 15 mph | 9 |
| Sun, Aug 30 | ⛈️ Thunderstorm | 85° / 77° | 86% · 0,9 in | 17 mph | 3 |
| Mon, Aug 31 | ⛈️ Thunderstorm | 84° / 76° | 89% · 1,0 in | 13 mph | 3 |
| Tue, Sep 1 | 🌦️ Drizzle | 87° / 76° | 94% · 0,4 in | 14 mph | 6 |
| Wed, Sep 2 | 🌦️ Light showers | 83° / 79° | 98% · 0,7 in | 15 mph | 1 |
| Thu, Sep 3 | 🌦️ Light showers | 85° / 77° | 86% · 0,8 in | 12 mph | 1 |
| Fri, Sep 4 | ⛈️ Thunderstorm | 85° / 76° | 84% · 1,1 in | 13 mph | 5 |
| Sat, Sep 5 | 🌦️ Light showers | 82° / 76° | 90% · 1,1 in | 20 mph | 8 |
| Sun, Sep 6 | 🌦️ Light showers | 84° / 78° | 91% · 0,6 in | 22 mph | 8 |
| Mon, Sep 7 | 🌦️ Drizzle | 89° / 76° | 85% · 0,2 in | 16 mph | 9 |
| Tue, Sep 8 | 🌦️ Drizzle | 88° / 76° | 86% · 0,3 in | 16 mph | 7 |
| Wed, Sep 9 | 🌦️ Drizzle | 83° / 82° | 69% · 0,2 in | 18 mph | 5 |
What this means for Guam
Today is slightly warmer than average for August. The forecast high of 90°F is 2.7°F above the 87°F typical for this month.
A 94% chance means rain is expected over most of the area. Plan indoor alternatives.
Wet roads are likely; braking distances roughly double in heavy rain.
Within 15 degrees of the equator, day length barely changes all year; seasons are defined by rain, not temperature.
Northern Hemisphere, so peak summer falls in June to August.
The gap between the warmest and coldest month averages 34°F - an unusually even climate through the year.
See the Guam forecast by time range
Guam weather - more answers
Explore Guam
Every topic we hold for this place, and the same topic for the places around it.
Weather for related places
Frequently asked questions
Where is Guam?
Guam is a country in Oceania. Its coordinates are 13.4443, 144.7937. It lies in Oceania.
What is the weather like in Guam right now?
It is currently 89°F (32°C) with overcast. Humidity is 61% and wind is 11 mph.
When is the best time to visit Guam?
January, February and December offer the most comfortable conditions in Guam, which has a tropical climate. July, August and September are usually the hardest months for outdoor plans.
What time zone is Guam in?
Guam observes Pacific/Guam (UTC+10:00). The local time is 1:08 PM.
How many people live in Guam?
Guam has a population of approximately 170.000.
Related articles
Data sources and methodology
| Place data | USPOTUS Atlas dataset (countries-v1) - coordinates, hierarchy and facts. |
|---|---|
| Forecast and observations | Open-Meteo (ECMWF and national models). |
| Air quality and pollen | Copernicus CAMS via Open-Meteo. US AQI scale. |
| Climate averages | ERA5 reanalysis via the Open-Meteo archive, aggregated over 3 years. |
| Method | Scores, comparisons and advice on this page are computed from the inputs above. Distances are straight-line. Nothing is estimated where data is missing - the block is simply not shown. |
Last updated August 25, 2026 at 1:08 PM local time. Live blocks refresh every 15 minutes; climate averages monthly.
