January weather forecastHagåtña, GU
January
Weather in January
Step into the new year in Hagåtña, Guam with a pleasant tropical climate, dominating the city throughout the month. Here, the days remain warm, though the evenings bring a couple of degrees drop providing a comfortable respite. A mix of clear skies and overcast days are anticipated with a moderate chance of breezy winds. January experiences the broad swing of relative humidity from a mild 77% to a high 78%. This is combined with an average of 21.3 rainy days, recording an accumulated rainfall of 2.83" (72mm), an adequate amount to keep the region lush and green.Temperature
At the start of January, Hagåtña's average high-temperature reaches a still warm 82°F (27.8°C), subtly different from the preceding month. During the January nights, Hagåtña's temperature maintains an average close to the daytime highs, settling at a still moderately hot 80.6°F (27°C).Heat index
In January, the heat index is appraised at a tropical 87.8°F (31°C). A sense of exhaustion might occur with extended exposure and activity, potentially causing heat cramps.Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to unobstructed sunshine could lead to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', binds temperature metrics with humidity values to give a sense of the actual warmth. Elements such as metabolic variations, being pregnant, and physical activity can impact one's weather perception. In direct sunlight, the heat's impact can be heightened, potentially leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Juveniles often do not understand the need to recuperate and rehydrate. Thirst is a delayed symptom of dehydration - hence, it is vital to maintain hydration, particularly during ongoing physical activities.
Humidity
January, March through May, October through December, with an average relative humidity of 78%, are the most humid months.Rainfall
In Hagåtña, during January, the rain falls for 21.3 days and regularly aggregates up to 2.83" (72mm) of precipitation. In Hagåtña, during the entire year, the rain falls for 288.5 days and collects up to 60.08" (1526mm) of precipitation.Ocean temperature
In Hagåtña, in January, the average water temperature is 82.9°F (28.3°C).Note: Water temperature ranging between 77°F (25°C) and 84.2°F (29°C) is considered very warm and pleasing for everyone. It allows for enjoyable water activities over extended periods without discomfort.
Daylight
In Hagåtña, the average length of the day in January is 11h and 26min.On the first day of the month, sunrise is at 6:43 am and sunset at 6:04 pm. On the last day of January, sunrise is at 6:47 am and sunset at 6:20 pm ChST.
Sunshine
In Hagåtña, Guam, the average sunshine in January is 7.6h.UV index
The months with the highest UV index are January through August, October through December, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: An average maximum UV index of 7 in January leads to these recommendations:
Implement precautions and maintain sun safety methods. Avoidance of sunburn is demanded. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. Tightly woven clothing, when worn loosely, shields effectively against the Sun. Notice! The reflection of water and sand increases the UV radiation significantly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in January
Hagåtña, GU
- Average high temperature in January: 82°F
The warmest months (with the highest average high temperature) are July and August (84.7°F).
The month with the lowest average high temperature is February (81.7°F).
- Average low temperature in January: 80.6°F
The month with the highest average low temperature is June (83.3°F).
The coldest month (with the lowest average low temperature) is February (79.7°F).
Average pressure in January
Hagåtña, GU
- Average pressure in January: 29.86"Hg
The month with the highest atmospheric pressure is February (29.88"Hg).
The months with the lowest atmospheric pressure are August, September and October (29.79"Hg).
Average wind speed in January
Hagåtña, GU
- Average wind speed in January: 15.8mph
The windiest month (with the highest average wind speed) is February (16.3mph).
The calmest month (with the lowest average wind speed) is August (9.6mph).
Average humidity in January
Hagåtña, GU
- Average humidity in January: 78%
The months with the highest relative humidity are January, March, April, May, October, November and December (78%).
The month with the lowest relative humidity is August (76%).
Average rainfall in January
Hagåtña, GU
- Average rainfall in January: 2.83"
The wettest month (with the highest rainfall) is September (10.28").
The driest month (with the least rainfall) is March (1.81").
Average rainfall days in January
Hagåtña, GU
- Average rainfall days in January: 21.3 days
The months with the highest number of rainy days are July and August (28.9 days).
The month with the least rainy days is February (17.5 days).
Average sea temperature in January
Hagåtña, GU
- Average sea temperature in January: 82.9°F
The best month for swimming (with the highest average sea temperature) is August (85.4°F).
The coldest month (with the lowest average sea temperature) is February (82°F).
Average daylight in January /
Average sunshine in January
Hagåtña, GU
- Average daylight in January: 11h and 24min
The month with the longest days is June (Average daylight: 12h and 54min).
The month with the shortest days is December (Average daylight: 11h and 18min).
- Average sunshine in January: 7h and 36min
The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is November (Average sunshine: 6h and 18min).
Average sunshine days in January
Hagåtña, GU
- Average sunshine days in January: 5.4 days
The month with the most sunshine days is March (6.6 days).
The month with the least sunshine days is September (1.1 days).
Average UV index in January
Hagåtña, GU
- Average UV index in January: 7
The months with the highest UV index are January, February, March, April, May, June, July, August, October, November and December (UV index 7).
The month with the lowest UV index is September (UV index 6).
Average cloud cover in January
Hagåtña, GU
- Average cloud cover in January: 46
The months with the most cloud cover are January, August and October (Cloud cover 46).
The months with the least cloud cover are May and June (Cloud cover 39).
Average visibility in January
Hagåtña, GU
- Average visibility in January: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





