September weather forecast
Hagåtña, GU

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Weather in September

September in Hagåtña, Guam, delivers yet another month of moderate tropical weather marked by hot days and cool nights. This is an ideal period for visitors looking to immerse in the local traditions and community gatherings. Expect frequent rains, with a total accumulated precipitation of 10.28" (261mm) falling over 28.1 days. The consistency of the weather, combined with the allure of various festivals, gives September a charm of its own.

Temperature

September commences in Hagåtña with an average high-temperature of a still warm 84.4°F (29.1°C), showing little deviation from August's 84.7°F (29.3°C). Hagåtña, in September, registers a nighttime average temperature of 82.8°F (28.2°C).

Heat index

The heat index value during September is computed to be a hot 93.2°F (34°C). Adopt heightened safety measures, heat cramps and heat exhaustion may occur. Sustained activity might cause heatstroke.
Evaluating the heat index requires understanding its values in the shade and with gentle winds. Under direct sunshine, the heat index values might be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', is an indicator that blends the effects of temperature and humidity to depict perceived warmth. Additional elements including metabolic differences, the level of physical activity, and attire have a role in shaping the individual's temperature perception. You should know that direct sun exposure can heighten weather effects, potentially elevating the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Youngsters typically face more danger than adults since they sweat less. Their larger skin surface compared to their small bodies and heightened heat production from their activities augment their vulnerability.

Humidity

In Hagåtña, the average relative humidity in September is 77%.

Rainfall

September is the month with the most rainfall in Hagåtña. Rain falls for 28.1 days and accumulates 10.28" (261mm) of precipitation.

Ocean temperature

In September, the average ocean temperature is 85.1°F (29.5°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 Hagåtña, the average length of the day in September is 12h and 13min.
On the first day of September in Hagåtña, sunrise is at 6:09 am and sunset at 6:32 pm. On the last day of the month, sunrise is at 6:10 am and sunset at 6:11 pm ChST.

Sunshine

In Hagåtña, the average sunshine in September is 7.9h.

UV index

The month with the lowest UV index in Hagåtña is September, with an average maximum UV index of 6. A UV Index estimate of 6 to 7 represents a high threat to health from unsafe exposure to UV radiation for average individuals.
Note: The daily maximum UV index of 6 in September interprets into the following advice:
Stay clear of intense sun exposure. Solar protection is of utmost significance. Avoid direct sunlight between the hours of 10 a.m. and 4 p.m., when UV radiation is at its peak. Keep in mind that shade structures may not provide complete protection. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Caution! Sand and water surfaces escalate the UV intensity from the Sun.
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Frequently asked questions

How hot does it get in Hagåtña in September?

The high-temperature, in September, in Hagåtña, is 84.4°F (29.1°C), while the low-temperature averages to 82.8°F (28.2°C). In September, the average heat index (a.k.a. 'feels like', 'felt air temperature'), which combines relative humidity and air temperature, is computed to be 93.2°F (34°C).

What is the average humidity in September in Hagåtña?

In Hagåtña, Guam, the average relative humidity in September is 77%.

What is the rainiest month in Hagåtña?

September is the month with the most rainfall in Hagåtña, Guam. Rain falls for 28.1 days and accumulates 10.28" (261mm) of precipitation.

How many days does it rain in September in Hagåtña?

In Hagåtña, Guam, during September, the rain falls for 28.1 days and regularly aggregates up to 10.28" (261mm) of precipitation.

What is the water temperature in September in Hagåtña?

In Hagåtña, the average seawater temperature in September is 85.1°F (29.5°C). 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.

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

In September, the average day length in Hagåtña is 12h and 13min.

When are sunrise and sunset in September in Hagåtña?

On the first day of September, sunrise is at 6:09 am and sunset at 6:32 pm. On the last day of the month, sunrise is at 6:10 am and sunset at 6:11 pm ChST.

How many hours of sunshine does Hagåtña have in September?

The average sunshine duration in September is 7.9h.

What is the month with the lowest UV index in Hagåtña?

The month with the lowest UV index in Hagåtña, Guam, is September, with an average maximum UV index of 6.

What is the UV index reading in September in Hagåtña?

In September, the average daily maximum UV index is 6. A UV Index estimate of 6 to 7 represents a high health risk from exposure to the Sun's UV radiation.

Average temperature in September
Hagåtña, GU

Average temperature in September - Hagåtña, GU
  • Average high temperature in September: 84.4°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 September: 82.8°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).

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Average pressure in September
Hagåtña, GU

Average pressure in September - Hagåtña, GU
  • Average pressure in September: 29.79"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).

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Average wind speed in September
Hagåtña, GU

Average wind speed in September - Hagåtña, GU
  • Average wind speed in September: 9.9mph

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).

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Average humidity in September
Hagåtña, GU

Average humidity in September - Hagåtña, GU
  • Average humidity in September: 77%

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%).

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Average rainfall in September
Hagåtña, GU

Average rainfall in September - Hagåtña, GU
  • Average rainfall in September: 10.28"

The wettest month (with the highest rainfall) is September (10.28").
The driest month (with the least rainfall) is March (1.81").

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Average rainfall days in September
Hagåtña, GU

Average rainfall days in September - Hagåtña, GU
  • Average rainfall days in September: 28.1 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).

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Average sea temperature in September
Hagåtña, GU

Average sea temperature in September - Hagåtña, GU
  • Average sea temperature in September: 85°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).

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Average daylight in September /
Average sunshine in September
Hagåtña, GU

Average daylight in September / Average sunshine in September - Hagåtña, GU
  • Average daylight in September: 12h and 1min

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 September: 7h and 5min

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).

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Average sunshine days in September
Hagåtña, GU

Average sunshine days in September - Hagåtña, GU
  • Average sunshine days in September: 1.1 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).

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Average UV index in September
Hagåtña, GU

Average UV index in September - Hagåtña, GU
  • Average UV index in September: 6

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).

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Average cloud cover in September
Hagåtña, GU

Average cloud cover in September - Hagåtña, GU
  • Average cloud cover in September: 45

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).

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Average visibility in September
Hagåtña, GU

Average visibility in September - Hagåtña, GU
  • Average visibility in September: 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).

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Hagåtña, Guam, USA

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