Hagåtña
Guam, USA
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
Hagåtña, GU

December, the first month of the winter, in Hagåtña, is still a warm month, with average temperature fluctuating between 82°F (27.8°C) and 83.5°F (28.6°C).

Temperature

In Hagåtña, the average high-temperature in December is almost the same as in November - a still moderately hot 83.5°F (28.6°C). The average low-temperature, in Hagåtña, Guam, is 82°F (27.8°C).

Heat index

In December, the average heat index is evaluated at a hot 91.9°F (33.3°C). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Take into consideration that the heat index values are calculated for shade and light wind conditions. 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 'real feel', 'felt air temperature', 'feels like', or 'apparent temperature', is calculated by taking the relative humidity value for a specific location and factoring it into the air temperature reading. Additional factors like activity, clothing, metabolic differences, and pregnancy affect individual temperature impact. Be aware that direct exposure to sunlight increases heat impact, and may raise the heat index additionally, 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.

Rainfall

In Hagåtña, Guam, during 22.8 rainfall days, 2.99" (76mm) of precipitation is typically accumulated. Throughout the year, there are 288.5 rainfall days, and 60.08" (1526mm) of precipitation is accumulated.

Ocean temperature

In December, the average ocean temperature is 83.1°F (28.4°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 month with the shortest days in Hagåtña is December, with an average of 11.3h of daylight.

Sunshine

The average sunshine in Hagåtña is 6.5h.

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 of 6 to 7 symbolizes a high health risk from unprotected exposure to the Sun's UV rays for the average person.
Note: The average daily UV index of 7 transform into the following instructions:
Take precautions against overexposure. Protection against sun damage is needed. 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. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.

What is the temperature in December in Hagåtña?

In Hagåtña, Guam, in December, the average high-temperature is 83.5°F (28.6°C), and the average low-temperature is 82°F (27.8°C). The average heat index (a.k.a. 'felt air temperature', 'feels like'), that factores the actual air temperature with the relative humidity, in December is appraised at 91.9°F (33.3°C).

What is the most humid month in Hagåtña?

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

What is the average humidity in December in Hagåtña?

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

How much does it rain in Hagåtña in December?

In Hagåtña, Guam, in December, it is raining for 22.8 days, with typically 2.99" (76mm) of accumulated precipitation.

How warm is the water in December in Hagåtña?

In Hagåtña, Guam, in December, the average water temperature is 83.1°F (28.4°C). For any water activity, surface water temperatures between 77°F (25°C) and 84.2°F (29°C) are considered as excellent and extremely pleasant for lengthened periods.

What is the month with the shortest days in Hagåtña?

December has the shortest days of the year, with an average of 11.3h of daylight.

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

In December, the average length of the day in Hagåtña, Guam, is 11.3h.

How many hours of sunshine does Hagåtña have in December?

In December, the average sunshine is 6.5h.

When is the highest UV index in Hagåtña?

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

What is the UV index intensity in December in Hagåtña?

In December, the average daily maximum UV index in Hagåtña is 7. A UV Index value of 6 to 7 symbolizes a high health risk from the exposure to the Sun's UV radiation.
Average temperature in December - Hagåtña, GU
  • Average high temperature in December: 28.6°C

The warmest months (with the highest average high temperature) are July and August (29.3°C).
The month with the lowest average high temperature is February (27.6°C).

  • Average low temperature in December: 27.8°C

The month with the highest average low temperature is June (28.5°C).
The coldest month (with the lowest average low temperature) is February (26.5°C).

Average humidity in December - Hagåtña, GU
  • Average humidity in December: 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 December - Hagåtña, GU
  • Average rainfall in December: 76mm

The wettest month (with the highest rainfall) is September (261mm).
The driest month (with the least rainfall) is March (46mm).

Average rainfall days in December - Hagåtña, GU
  • Average rainfall days in December: 22.8 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 December - Hagåtña, GU
  • Average sea temperature in December: 28.4°C

The best month for swimming (with the highest average sea temperature) is August (29.7°C).
The coldest month (with the lowest average sea temperature) is February (27.8°C).

Average daylight in December / Average sunshine in December - Hagåtña, GU
  • Average daylight in December: 11.3h

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 December: 6.5h

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 UV index in December - Hagåtña, GU
  • Average UV index in December: 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).