January weather forecast
Hagåtña, GU

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

In the transition from December to January, Hagåtña reports an average high-temperature of a still warm 82°F (27.8°C), indicating a close resemblance to the prior month. The nights of January cool down to an average low of 80.6°F (27°C), subtly lower than daytime highs.

Heat index

The heat index value during January is computed to be a tropical 87.8°F (31°C). Enduring exposure and unrelenting activity might cause a state of weariness, potentially leading to heat cramps.
Heat index readings emphasize conditions of light breezes and shaded spots. Heat index values have the potential to be boosted by 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'apparent temperature' or 'real feel', is derived by integrating air temperature with the existing relative humidity to express the perceived warmth. Factors encompassing physical activity, clothing, and metabolic differences have a role in shaping the individual's impression of temperature. Direct exposure to the sun's rays can enhance the felt temperature, increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Young kids are often more at risk than adults as they tend to perspire less. Besides, their skin surface is larger relative to their small bodies, and their increased heat output from their active lifestyle compounds their risk.

Humidity

The months with the highest humidity in Hagåtña are January, March through May, October through December, with an average relative humidity of 78%.

Rainfall

In January, the rain falls for 21.3 days. Throughout January, 2.83" (72mm) of precipitation is accumulated. 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, Guam, the average seawater temperature in January is 82.9°F (28.3°C).
Note: Between 77°F (25°C) and 84.2°F (29°C), water temperature is typically considered very warm and pleasurable by everyone. Water activities at these temperatures are enjoyable for extended periods without discomfort.

Daylight

In January, the average length of the day 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, in Hagåtña, sunrise is at 6:47 am and sunset at 6:20 pm ChST.

Sunshine

The average sunshine in January in Hagåtña is 7.6h.

UV index

The months with the highest UV index in Hagåtña 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 hazard from unprotected exposure to Sun's UV rays for average individuals.
Note: In January, a regular UV index of 7 translates into these guidelines:
Ward off overexposure. Defence against solar harm is crucial. Avoid direct Sun exposure and stay in the shade between 10 a.m. and 4 p.m., a time when UV radiation is most intense, noting that not all shade structures offer full protection. A hat with a broad brim is indispensable, filtering out up to half of UV rays. Be vigilant! The Sun's UV rays get a boost from sand and water reflections.