Guam Climate and Average Weather
Climate of Guam: average temperatures, rainfall and seasons month by month.
Climate in Guam month by month
Average high, average low and total rainfall, based on three years of reanalysis data.
| Month | Avg high | Avg low | Rainfall | Rating |
|---|---|---|---|---|
| January | 87° | 78° | 2,5 in | ★★★★☆ |
| February | 87° | 77° | 2,4 in | ★★★★☆ |
| March | 87° | 77° | 4,7 in | ★★★★☆ |
| April | 88° | 78° | 5,0 in | ★★★☆☆ |
| May | 89° | 78° | 5,4 in | ★★★☆☆ |
| June | 89° | 78° | 8,7 in | ★★★☆☆ |
| July | 88° | 78° | 16,6 in | ★★☆☆☆ |
| August | 87° | 77° | 12,3 in | ★★☆☆☆ |
| September | 86° | 77° | 18,1 in | ★★☆☆☆ |
| October | 86° | 77° | 14,7 in | ★★☆☆☆ |
| November | 87° | 78° | 5,5 in | ★★★☆☆ |
| December | 87° | 78° | 3,1 in | ★★★★☆ |
Climate type: Tropical. Source: Open-Meteo archive (ERA5).
Recent extremes in Guam
Highest and lowest readings observed in the last 3 years of reanalysis data - not all-time records.
Best time to visit Guam
Go in January, February and December. These months score highest on comfortable temperatures, low rainfall and useful daylight.
Hardest months: July, August and September - expect the least comfortable mix of heat, cold or rain.
What this means for Guam
Today is slightly warmer than average for August. The forecast high of 90°F is 3.1°F above the 87°F typical for this month.
A 93% 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.
What to pack, what to skip
- Lightweight, light-coloured clothing and a refillable water bottle
- Sunglasses, a brimmed hat and SPF 30+
- A packable rain shell - 7 of the next 7 days carry a real chance of rain
- Insect repellent and quick-dry fabrics for humidity
- If your dates are flexible, avoid July, August and September - historically the least comfortable months here.
Summary
Guam is a country in Oceania. Guam is a country in Oceania with its capital at Hagatna. It has a population of about 170.000. The capital is Hagatna.
Right now it is 82°F (28°C) in Guam with overcast. It feels like 89°F. Today runs from 79°F to 90°F. Chance of precipitation is 93%. Sightseeing conditions score 6.8/10 - fair - plan around the weather.
The best time to visit Guam is January, February and December. The climate is tropical. July, August and September tend to be the least comfortable months. May is the warmest month with average highs near 89°F, while March is the coldest with lows near 77°F.
In plain terms. Today is slightly warmer than average for August. The forecast high of 90°F is 3.1°F above the 87°F typical for this month. The best window to be outside is roughly 7 AM to 10 AM, when temperature, rain chance and wind line up best. fishing is the strongest bet in Guam today at 8.7/10. Wet roads are likely; braking distances roughly double in heavy rain.
Compiled from this page's own data: atlas facts plus live Open-Meteo readings.
Quick facts about Guam
| Type | Country |
|---|---|
| Continent | Oceania |
| Continent | Oceania |
| Coordinates | 13°26′39.5″N 144°47′37.3″E (13.4443, 144.7937) |
| Capital | Hagatna |
| Population | 170.000 |
| Area | 210 sq mi |
| ISO code | GU |
| ISO 3166-1 alpha-3 | GUM |
| Currency | US dollar (USD) |
| Languages | English, Chamorro |
| Calling code | +1-671 |
| Time zone | Pacific/Guam |
| Local time | 7:47 PM (UTC+10:00) |
| Best months | January, February and December |
| Climate | Tropical |
Weather map for Guam
Animated model layers. Pick a layer to load it.
Animated layers by Windy. For pin-level detail and nearby places, see the interactive map below.
Explore Guam
Every topic we hold for this place, and the same topic for the places around it.
Climate 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 82°F (28°C) with overcast. Humidity is 82% and wind is 10 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 7:47 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 21, 2026 at 7:47 PM local time. Live blocks refresh every 15 minutes; climate averages monthly.
