January weather forecast and climate
Hagåtña, GU

January, like December, in Hagåtña, Guam, is a moderately hot winter month, with average temperature fluctuating between 80.6°F (27°C) and 82°F (27.8°C).

Temperature

In Hagåtña, the average high-temperature is relatively the same as in December - a still warm 82°F (27.8°C). The average low-temperature, in January, is 80.6°F (27°C).

Heat index

The average heat index in January is calculated to a tropical 88.3°F (31.3°C). Constant exposure and activity lead to possible fatigue. Prolonged exercise may result in heat cramps.
Note that heat index values are valued for light wind and location in the shade. With the exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like', 'apparent temperature', 'real feel', or 'felt air temperature', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. This effect is individual, with diverse people perceiving weather differently for numerous reasons (metabolic differences, wind, pregnancy), and activity. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.

Humidity

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

Rainfall

In Hagåtña, during January, the rain falls for 21.3 days and regularly aggregates up to 2.83" (72mm) of precipitation. Throughout the year, there are 288.5 rainfall days, and 60.08" (1526mm) of precipitation is accumulated.

Ocean temperature

In January, the average ocean temperature in Hagåtña is 82.9°F (28.3°C).
Note: Water temperature between 77°F (25°C) and 84.2°F (29°C) is regarded as very warm and enjoyable by all. With these temperatures, water activities are pleasurable, without feeling uncomfortable for prolonged periods.

Daylight

The average length of the day in Hagåtña is 11.4h.

Sunshine

In January, the average sunshine in Hagåtña is 7.6h.

UV index

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 reading of 6 to 7 represents a high health hazard from unsafe exposure to the UV radiation for the average person.
Note: The average daily UV index of 7 transform into the following instructions:
Take precautions and utilize sun safety practices. Protection against the skin and eye damage is required. 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. 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! The strength of the UV rays is significantly increased by the reflection of the water and sand.

What is the temperature in January in Hagåtña?

The average high-temperature, in January, is 82°F (27.8°C), while the average low-temperature is 80.6°F (27°C). The average heat index (a.k.a. 'apparent temperature', 'real feel'), that takes the relative humidity and factores it into the air temperature reading, in January is calculated to 88.3°F (31.3°C).

What are the most humid months in Hagåtña?

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

What is the average humidity in January in Hagåtña?

In Hagåtña, Guam, the average relative humidity in January is 78%.

How much does it rain in Hagåtña in January?

In Hagåtña, Guam, during January, the rain falls for 21.3 days and regularly aggregates up to 2.83" (72mm) of precipitation.

How warm is the water in January in Hagåtña?

In Hagåtña, the average seawater temperature in January is 82.9°F (28.3°C). For swimming, diving, and other water activities, temperatures between 77°F (25°C) and 84.2°F (29°C) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

What is the average length of the day in January in Hagåtña?

In January, the average length of the day in Hagåtña, Guam, is 11.4h.

How long on average sun shines in January in Hagåtña?

In Hagåtña, the average sunshine in January is 7.6h.

What are the months with the highest UV index in Hagåtña?

Months with the highest UV index in Hagåtña are January through August, October through December, with an average maximum UV index of 7.

How high is the UV index in January in Hagåtña?

In January, the average daily maximum UV index in Hagåtña is 7. A UV Index reading of 6 to 7 represents a high hazard to health from the exposure to the Sun's UV rays.
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"

The month with the highest atmospheric pressure is February (29.88").
Months with the lowest atmospheric pressure are August, September and October (29.79").

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%

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

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: 11.4h

The month with the longest days is June (Average daylight: 12.9h).
The month with the shortest days is December (Average daylight: 11.3h).

  • Average sunshine in January: 7.6h

The month with the most sunshine is June (Average sunshine: 10.6h).
The month with the least sunshine is November (Average sunshine: 6.3h).

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

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

Months with the most cloud cover are January, August and October (Cloud cover 46).
Months with the least cloud cover are May and June (Cloud cover 39).

Average visibility in January - Hagåtña, GU
  • Average visibility in January: 6mi

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).