Agat Weather in January (1981–2025)

📍 13.36°N, 144.66°E •
📊

January at a Glance in Agat

(1981–2025)
Avg High
🔥
27.7°C
Avg Low
❄️
27.0°C
Avg Temp
🌡️
27.4°C
Avg Rain
🌧️
76 mm
Avg Humidity
💧
78%
Avg Wind
🌬️
6.4 m/s
Avg Solar
☀️
4.9
kWh/m²/day
vs Annual
📈
-0.6°C
temp difference
🌡️Warm afternoons🌙Warm mornings🌤️Fairly sunny🌧️Wet month🌬️Windy💦Humid air

Agat January Weather Overview

January is one of the cooler months of the year in Agat, with average highs near 27.7°C and lows around 27°C (mean 27.4°C). It is one of the drier months, averaging 76 mm of rainfall and 78% relative humidity across the period.

Agat January Temperature History (1981–2025)

Range

January is one of the cooler months of the year in Agat. Across 45 years of records, the warmest January in Agat was 2025 — when the month averaged 28.4°C — while the coldest was 1983 at 26.1°C. Typical January days reach 27.7°C with nights near 27°C. The long-term trend is warming, about 0.2°C per decade.

1981–1985 vs 2021–2025

Avg Temp27.0°C→28.0°C+1°C
Max Temp27.4°C→28.3°C+0.9°C
Min Temp26.7°C→27.6°C+0.9°C

Trend (per decade)

Avg Temp+0.2°C/decade ↗
Max Temp+0.2°C/decade ↗
Min Temp+0.2°C/decade ↗

Distribution of Avg Temp

26.0°C–26.8°C6 yr (13%)
26.8°C–27.5°C18 yr (40%)
27.5°C–28.3°C20 yr (44%)
28.3°C–29.0°C1 yr (2%)

Agat January Rainfall History (1981–2025)

Range

January is one of the drier months in Agat, averaging 76 mm of rainfall. The wettest January on record was 2014 with 284 mm, while the driest was 1993 at 10 mm.

Agat January Humidity History (1981–2025)

Range

Relative humidity in Agat during January averages 78%. The most humid January was 1997 at 82%, and the least humid was 1998 at 71%.

Agat January Solar History (1981–2025)

Range

January receives about 4.9 kWh/m²/day of solar energy in Agat. The sunniest January was 2018 at 5.4 kWh/m²/day, and the cloudiest was 1997 at 4.2.

Agat January Wind History (1981–2025)

Range

Average wind speed in Agat during January is 6.4 m/s. The windiest January was 1990 at 7.7 m/s, while the calmest was 1982 at 5.2 m/s.

What January Feels Like in Agat

🌅
Warm
Morning
🌞
Warm
Afternoon
🌆
Warm
Evening
Rain chanceModerate
Outdoor comfort★★★★☆

How January Ranks in Agat

🥶3rd coolest month of the year
🌵5th driest month of the year
☀️11th sunniest month of the year

Ranked against the other 11 months using 1981–2025 averages.

Explore Agat Weather by Month

Agat January Averages by Decade

Metric1980s1990s2000s2010s2020sChange
Avg Temp27.1°C27.0°C27.5°C27.6°C27.8°C+0.7°C
Avg High27.4°C27.4°C27.9°C28.0°C28.2°C+0.8°C
Avg Low26.7°C26.6°C27.1°C27.2°C27.5°C+0.8°C
Avg Rain64 mm64 mm71 mm98 mm84 mm+21 mm

Extreme January Records in Agat

🔥Warmest January29.3°C2013
🧊Coldest January24.7°C1983
🌧️Wettest January284 mm2014
🏜️Driest January10 mm1993
🌬️Windiest January7.7 m/s1990

Key Insights for January

✅

January temperatures in Agat have risen by about 1°C between 1981–1985 and 2021–2025.

✅

January has ranged from a record low of 24.7°C (1983) to a record high of 29.3°C (2013).

✅

Rainfall in January is one of the drier months, averaging 76 mm, with a wettest year of 284 mm.

Is January a Good Time to Visit Agat?

One of the best times to visit Agat

January is one of the best times to visit Agat. Expect days averaging 27.7°C and nights around 27°C (mean 27.4°C) — close to Agat's yearly average — with moderate rainfall (76 mm), so conditions are generally comfortable for sightseeing and outdoor plans.

See Agat's complete weather history All 12 months side by side, 1981–2025 records, annual trends and long-term averages in one place. View full history →

Agat Weather in January — In Depth

☀️ January climate overview

January is one of the cooler months of the year in Agat, with average highs near 27.7°C and lows around 27°C (mean 27.4°C). It is one of the drier months, averaging 76 mm of rainfall and 78% relative humidity across the period.

🌧️ Rain, humidity & wind in January

January averages 76 mm of rainfall in Agat, one of the drier months compared with the rest of the year. The wettest January on record saw 284 mm (2014), and the driest just 10 mm (1993). Humidity sits around 78% and average wind speed is 6.4 m/s, with solar radiation averaging 4.9 kWh/m²/day.

📈 How January has changed

Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 1°C. Daytime highs moved from 27.4°C to 28.3°C and overnight lows from 26.7°C to 27.6°C over the same span.
January Weather in Agat, Year by Year
🔥 warmest❄️ coldest🌧️ wettest
YearAvg HighAvg TempAvg LowHottest DayColdest DayRainfallHumidityWindSolar
2025 🔥28.8°C28.4°C28.0°C29.2°C27.4°C37 mm77%5.9 m/s5.3
202428.2°C27.8°C27.5°C29.3°C26.5°C66 mm77%6.5 m/s4.9
202328.3°C28.0°C27.6°C28.7°C26.8°C202 mm80%5.5 m/s4.6
202228.1°C27.7°C27.3°C28.5°C26.6°C96 mm79%6.1 m/s4.7
202128.3°C27.9°C27.5°C28.9°C26.7°C47 mm78%6 m/s5.3
202027.6°C27.2°C26.9°C28.0°C26.4°C59 mm80%6.3 m/s4.8
201927.6°C27.3°C26.9°C28.1°C26.1°C72 mm79%7.1 m/s4.7
201828.4°C28.0°C27.6°C29.1°C26.6°C27 mm76%6.1 m/s5.4
201728.1°C27.8°C27.4°C28.8°C26.6°C96 mm80%6.3 m/s4.7
201627.7°C27.2°C26.8°C28.4°C26.0°C29 mm77%6 m/s5.3
201528.1°C27.7°C27.3°C28.7°C26.8°C151 mm81%5.8 m/s4.5
2014 🌧️28.1°C27.7°C27.3°C28.7°C26.5°C284 mm81%5.5 m/s4.4
201328.1°C27.7°C27.3°C29.3°C26.4°C44 mm77%6.8 m/s5
201227.8°C27.5°C27.1°C28.4°C26.1°C64 mm79%6.4 m/s4.9
201128.4°C28.0°C27.7°C28.8°C26.6°C138 mm80%6.2 m/s4.5
201027.5°C27.2°C26.9°C28.4°C26.2°C77 mm79%7.2 m/s4.6
200928.1°C27.7°C27.3°C28.6°C26.4°C79 mm78%6.3 m/s4.9
200828.1°C27.8°C27.4°C28.8°C26.8°C68 mm77%7 m/s4.9
200727.8°C27.4°C27.1°C28.4°C26.5°C53 mm78%7.6 m/s4.9
200628.1°C27.8°C27.4°C28.7°C26.0°C164 mm78%6.9 m/s4.7
200527.5°C27.2°C26.8°C28.5°C25.9°C70 mm76%6.5 m/s4.6
200428.0°C27.6°C27.2°C28.5°C26.4°C57 mm76%6.7 m/s4.9
200327.9°C27.5°C27.1°C28.7°C26.2°C38 mm76%6.4 m/s5.2
200227.7°C27.3°C27.0°C28.2°C26.2°C114 mm77%6.6 m/s4.8
200128.0°C27.7°C27.3°C28.4°C26.5°C39 mm76%6.3 m/s5.1
200027.6°C27.2°C26.8°C28.4°C25.9°C29 mm76%6 m/s5.1
199927.9°C27.6°C27.2°C28.8°C26.3°C92 mm78%6.4 m/s4.9
199827.7°C27.3°C26.9°C28.3°C26.2°C22 mm71%6.7 m/s5
199727.7°C27.4°C27.1°C28.5°C26.4°C163 mm82%5.6 m/s4.2
199628.0°C27.5°C27.1°C29.1°C25.8°C86 mm78%6.8 m/s4.5
199527.0°C26.7°C26.3°C27.9°C25.8°C15 mm77%6.7 m/s4.8
199427.4°C27.0°C26.6°C28.0°C26.1°C45 mm78%6.1 m/s5
199326.8°C26.4°C26.0°C27.3°C25.4°C10 mm75%7 m/s5
199227.1°C26.7°C26.3°C27.6°C25.9°C90 mm78%7 m/s4.6
199126.8°C26.5°C26.2°C27.4°C25.6°C18 mm78%6.9 m/s5
199027.4°C27.1°C26.7°C28.6°C25.8°C100 mm80%7.7 m/s4.8
198928.2°C27.8°C27.4°C28.7°C26.9°C20 mm79%6.9 m/s5.1
198827.5°C27.1°C26.7°C28.1°C26.2°C56 mm78%7.3 m/s5
198726.8°C26.4°C26.1°C27.6°C24.8°C22 mm81%6.5 m/s5
198627.4°C27.1°C26.7°C28.3°C25.7°C22 mm79%6.9 m/s5.1
198527.4°C27.1°C26.8°C27.9°C26.2°C127 mm81%6.2 m/s4.6
198427.6°C27.2°C26.8°C28.8°C25.9°C67 mm78%5.7 m/s4.6
1983 ❄️26.5°C26.1°C25.8°C27.1°C24.7°C23 mm77%6.4 m/s—
198227.7°C27.4°C27.0°C28.5°C25.4°C104 mm79%5.2 m/s—
198127.7°C27.4°C27.0°C28.3°C26.4°C134 mm80%6 m/s—

Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.

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Agat January Weather — FAQ

What is the average temperature in Agat in January?▼

The average high in January is around 27.7°C with lows near 27°C (mean 27.4°C), based on 45 years of NASA POWER data.

Does it rain a lot in Agat in January?▼

January averages 76 mm of rainfall in Agat, one of the drier months. The wettest on record was 284 mm in 2014.

What was the hottest January on record in Agat?▼

The hottest January reached 29.3°C in 2013. The coldest dipped to 24.7°C in 1983.

Has January in Agat gotten warmer over time?▼

Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 1°C. Daytime highs moved from 27.4°C to 28.3°C and overnight lows from 26.7°C to 27.6°C over the same span.

Is January a good time to visit Agat?▼

January is one of the cooler months of the year in Agat and one of the drier months, so plan for around 27.7°C daytime highs and 27°C at night.

Is January the coldest month in Agat?▼

Not quite — January is the 3rd coolest month in Agat, averaging 27.4°C.

What should I pack for Agat in January?▼

For January in Agat, pack light layers you can adjust through the day, with typical highs of 27.7°C and lows of 27°C. Bring an umbrella or light rain jacket too.

Is Agat humid in January?▼

Relative humidity in January averages 78% — quite humid.

How windy is Agat in January?▼

Average wind speed in January is 6.4 m/s. The windiest January on record averaged 7.7 m/s (1990).

Which January had the most rainfall in Agat?▼

The wettest January on record was 2014 with 284 mm. On average, January sees 76 mm.

Where does this January weather data come from?▼

All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.

Other Guam cities

Explore how the weather in Agat behaves each January, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for January specifically, along with year-by-year records and how the month has changed over the decades.