Agat has a warm subtropical climate with warm summers and mild winters.
Temperatures peak in June and drop to their lowest in February, while rainfall is highest during summer months.
Humidity remains high throughout the year creating warm and humid conditions.
| Month | 🌤️ | Avg High | Avg Temp | Avg Low | Record High | Record Low | Humid % | Rain (mm) | Wind (m/s) | Solar (kWh/m²) |
|---|---|---|---|---|---|---|---|---|---|---|
| January | 🌞 | 82.0°F | 81.3°F | 80.6°F | 84.7°F | 76.5°F | 78% | 76 | 6.4 | 4.85 |
| February | 🌞 | 81.4°F | 80.7°F | 80.0°F | 84.2°F | 76.1°F | 78% | 49 | 6.5 | 5.44 |
| March | 🌞 | 81.8°F | 81.0°F | 80.2°F | 84.2°F | 75.4°F | 77% | 39 | 6.2 | 6.22 |
| April | 🌞 | 82.9°F | 82.0°F | 81.2°F | 85.6°F | 77.5°F | 78% | 46 | 5.7 | 6.69 |
| May | 🔥 | 83.8°F | 83.0°F | 82.2°F | 86.5°F | 78.6°F | 79% | 56 | 5.0 | 6.64 |
| June | ☔ | 84.2°F | 83.4°F | 82.6°F | 87.1°F | 78.3°F | 80% | 96 | 4.7 | 6.28 |
| July | 🌧️ | 83.7°F | 83.0°F | 82.3°F | 86.7°F | 78.8°F | 81% | 197 | 4.2 | 5.59 |
| August | 🌧️ | 83.5°F | 82.8°F | 82.1°F | 87.3°F | 77.9°F | 82% | 277 | 4.2 | 5.18 |
| September | 🌧️ | 83.6°F | 82.8°F | 82.1°F | 86.5°F | 78.4°F | 82% | 252 | 4.1 | 5.09 |
| October | 🌧️ | 83.7°F | 83.0°F | 82.4°F | 86.2°F | 78.6°F | 82% | 203 | 4.6 | 5.04 |
| November | ☔ | 83.9°F | 83.3°F | 82.7°F | 86.2°F | 79.3°F | 80% | 137 | 5.9 | 5.01 |
| December | ☔ | 83.1°F | 82.5°F | 81.9°F | 85.8°F | 78.1°F | 79% | 84 | 6.5 | 4.77 |
Showing average climate conditions across 45 years (1981–2025)
🧥 Light layers are sufficient — this Mild Winter stays cool without prolonged hard freezes.
🌤️ Early mornings and evenings are most comfortable during this Hot Summer season.
☔ Heavy Rainfall expected — carry rain gear and plan outdoor activities around these months.
Monthly averages · 1981–2025 climate normals · °F
Temperatures rise steadily from spring, peak in June, and gradually decline through autumn into winter.
These seasonal patterns offer comfortable conditions year-round, with warm summers and mild winters.
Monthly rainfall · 1981–2025 seasonal trends · mm/month
Rainfall is concentrated in the summer months. Humidity stays high (around 80%), peaking during summer months, which creates warm and humid conditions.
☔ Heavy Rainfall expected — carry rain gear and plan outdoor activities around these months.
Monthly averages · 1981–2025
Across 45 years of records, Agat's temperature has remained relatively stable over the past decade. Its hottest day reached 87.3°F in August 2024, and its coldest dropped to 75.5°F in March 1983. 2025 was the warmest year overall and 1993 the coolest.
The warmest year in Agat's recorded history was 2025 (avg: 83.5°F), while the coldest was 1993 (avg: 81.1°F).
Average annual high/low · Last 30 years · °F
Total annual precipitation · Last 30 years · mm/year
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall (mm) | Avg Humidity | Avg Wind |
|---|---|---|---|---|---|---|---|---|
2025 🔥 | 84.2°F | 83.5°F | 82.6°F | 86.2°F | 80.2°F | 1652 | 80% | 4.8 m/s |
2024 | 84.2°F | 83.5°F | 82.6°F | 87.3°F | 78.6°F | 1336 | 80% | 5.2 m/s |
2023 | 84.0°F | 83.3°F | 82.6°F | 86.2°F | 79.7°F | 1779 | 81% | 5.2 m/s |
2022 | 83.8°F | 82.9°F | 82.2°F | 86.4°F | 79.3°F | 1459 | 80% | 4.8 m/s |
2021 | 84.0°F | 83.3°F | 82.4°F | 86.5°F | 80.1°F | 1539 | 79% | 4.6 m/s |
2020 | 83.7°F | 82.9°F | 82.2°F | 86.5°F | 78.4°F | 1036 | 79% | 5.2 m/s |
2019 | 83.5°F | 82.8°F | 82.0°F | 86.2°F | 78.6°F | 1528 | 79% | 5.2 m/s |
2018 | 83.5°F | 82.8°F | 82.0°F | 85.5°F | 78.4°F | 1655 | 81% | 5.2 m/s |
2017 | 84.0°F | 83.3°F | 82.6°F | 86.9°F | 79.5°F | 1469 | 80% | 4.8 m/s |
2016 | 83.7°F | 82.8°F | 82.0°F | 86.7°F | 78.6°F | 1363 | 79% | 5.1 m/s |
Showing 1 to 10 of 45 years
Based on 45 years of data (1981–2025), June is typically the hottest month in Agat, Guam, with average high temperatures around 84.2°F.
February is the coldest month in Agat, with average low temperatures around 80.0°F.
August receives the most rainfall with approximately 277 mm, while March is the driest with 39 mm.
The highest recorded temperature was 87.3°F in August 2024. This is part of the historical record spanning 1981–2025.
The lowest recorded temperature was 75.5°F in March 1983.
This page covers 45 years of climate data from 1981 to 2025. As new data is added to the database the page automatically reflects the updated coverage.
Agat receives the most sunlight in April with an average solar radiation of 6.69 kWh/m²/day. This solar radiation data, sourced from NASA POWER, is useful for solar energy planning and agriculture in Guam.
All climate data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite and model data. It provides monthly averages for temperature, precipitation, humidity, wind speed, and solar radiation.
All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.
