January weather forecast
Inarajan, GU

Weather conditions in Inarajan, Guam in January slowly transition from the relatively serene period seen in the earlier part of the winter season. The new year is greeted with a slight increase in rainfall to 2.83" (72mm) with 21.3 rainy days, making this month not so ideal for outdoor activities. However, coastal activities flourish with relatively warm sea temperatures, great for water sports and seaside relaxations. With 11.4 daylight hours and a UV index of 7, residents and tourists alike are advised to carry sun protection. Despite the prevalent rain, January hosts fairly generous sunlight hours reflecting the territory's tropical climate.

Temperature

January's presence records an average high-temperature of a still moderately hot 82°F (27.8°C), closely mirroring December's climate. In January, Inarajan's nighttime temperatures demonstrate a slight decrease, stabilizing at an average of 80.6°F (27°C).

Heat index

Throughout January, the heat index is evaluated at a tropical 87.8°F (31°C). Persisting in activity during exposure could lead to weariness and subsequently to heat cramps.
The metrics for the heat index are tailored for both shady environments and light winds. The heat index has the possibility to be enhanced by 15 Fahrenheit (8 Celsius) degrees when there is direct sun exposure.
Note: The heat index, also known as 'apparent temperature' or 'real feel', unifies temperature and humidity readings to offer a comprehensive feel of warmth. Factors encompassing physical activity, clothing, and metabolic differences have a role in shaping the individual's impression of temperature. It is noteworthy to mention that direct sunlight exposure can augment the felt temperature, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Youths are typically more endangered than adults since they usually sweat less. Their larger skin surface concerning their smaller bodies and higher heat production due to activity further adds to their vulnerability.

Humidity

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

Rainfall

In Inarajan, in January, it is raining for 21.3 days, with typically 2.83" (72mm) of accumulated precipitation. Throughout the year, in Inarajan, there are 288.5 rainfall days, and 60.08" (1526mm) of precipitation is accumulated.

Ocean temperature

In Inarajan, the average seawater temperature in January is 82.9°F (28.3°C).
Note: Engaging in swimming, diving, or other water activities is highly enjoyable in temperatures ranging from 77°F (25°C) to 84.2°F (29°C), without any unpleasant sensations for prolonged durations.

Daylight

In Inarajan, the average length of the day in January is 11h and 26min.
On the first day of January, sunrise is at 6:43 am and sunset at 6:05 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:20 pm ChST.

Sunshine

In January, the average sunshine in Inarajan 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 reading of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for the ordinary person.
Note: A maximum daily UV index of 7 during January morphs into the following directions:
Endorse precautions and be consistent with sun safety guidelines. Preventing sunburn is paramount. To the best of your ability, limit your exposure to the sun between the hours of 10 a.m. and 4 p.m., when UV radiation is at its peak. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Beware! Reflecting off water and sand, UV rays are much stronger.