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 | 🌤️ | High | Low | Avg | Humid % | Rain (mm) | Wind (m/s) | Solar (kWh/m²) |
|---|---|---|---|---|---|---|---|---|
| January | 🌞 | 83.2°F | 79.1°F | 81.1°F | 78% | 76 | 6.4 | 4.85 |
| February | 🌞 | 82.6°F | 78.7°F | 80.7°F | 78% | 49 | 6.5 | 5.44 |
| March | 🌞 | 83.0°F | 78.8°F | 80.9°F | 77% | 39 | 6.2 | 6.22 |
| April | 🌞 | 84.0°F | 79.8°F | 81.9°F | 78% | 46 | 5.7 | 6.69 |
| May | 🔥 | 85.0°F | 80.7°F | 82.8°F | 79% | 56 | 5.0 | 6.64 |
| June | ☔ | 85.4°F | 80.9°F | 83.1°F | 80% | 96 | 4.7 | 6.28 |
| July | 🌧️ | 85.2°F | 80.4°F | 82.8°F | 81% | 197 | 4.2 | 5.59 |
| August | 🌧️ | 85.1°F | 80.1°F | 82.6°F | 82% | 277 | 4.2 | 5.18 |
| September | 🌧️ | 85.1°F | 80.2°F | 82.7°F | 82% | 252 | 4.1 | 5.09 |
| October | 🌧️ | 85.1°F | 80.4°F | 82.8°F | 82% | 203 | 4.6 | 5.04 |
| November | ☔ | 84.9°F | 81.2°F | 83.0°F | 80% | 137 | 5.9 | 5.01 |
| December | ☔ | 84.3°F | 80.4°F | 82.3°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.
🌤️ Conditions are ideal for outdoor activities throughout the day in this Mild Summer.
☔ 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
Monthly averages · 1981–2025
💧 Humidity peaks at 82% in August · annual avg 80%
The warmest year in Agat's recorded history was 2025 (avg: 83.3°F), while the coldest was 1993 (avg: 81.0°F).
Average annual high/low · Last 10 years · °F
Total annual precipitation · Last 10 years · mm/year
| Year | Min Temp | Avg Temp | Max Temp | Rainfall (mm) | Avg Humidity | Avg Wind |
|---|---|---|---|---|---|---|
2025 | 81.1°F | 83.3°F | 85.3°F | 1652 | 80% | 4.8 m/s |
2024 🔥 | 81.0°F | 83.3°F | 85.5°F | 1336 | 80% | 5.2 m/s |
2023 | 81.0°F | 82.9°F | 85.1°F | 1779 | 81% | 5.2 m/s |
2022 | 80.8°F | 82.9°F | 85.1°F | 1459 | 80% | 4.8 m/s |
2021 | 81.1°F | 83.1°F | 85.1°F | 1539 | 79% | 4.6 m/s |
2020 | 80.4°F | 82.6°F | 84.7°F | 1036 | 79% | 5.2 m/s |
2019 | 80.4°F | 82.6°F | 84.7°F | 1528 | 79% | 5.2 m/s |
2018 | 80.2°F | 82.4°F | 84.6°F | 1655 | 81% | 5.2 m/s |
2017 | 80.8°F | 82.9°F | 85.3°F | 1469 | 80% | 4.8 m/s |
2016 | 80.6°F | 82.8°F | 84.9°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 85.4°F.
February is the coldest month in Agat, with average low temperatures around 78.7°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.
