September weather forecast
Umatac, GU

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Weather in September

September weather in Umatac, Guam juxtaposes elevated rainfall, peaking at 10.28" (261mm) alongside significantly reduced sunshine. This denotes a continuation of the rainy season, with rainfall being the most distinguishing feature, even when compared to August. Reduced daylight hours cast an overcast temperament over the city. The atmosphere compensates with soothing temperatures and moderated wind speeds. Still, the unwavering UV index does not relent, maintaining a consistent strength.

Temperature

The commencement of September in Umatac notes an average high-temperature of a still warm 84.4°F (29.1°C), exhibiting little difference from the previous month. In Umatac, the September nights are characterized by an average low-temperature of 82.8°F (28.2°C), a minor dip from daytime readings.

Heat index

The heat index value for September is computed to be a hot 93.2°F (34°C). Undertake enhanced precautions, heat exhaustion and heat cramps are possible risks. Continuous activity could trigger heatstroke.
Heat index details are generally centered around shaded locations and a mild breeze. Being under direct sunlight might amplify the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', takes into account both air temperature and humidity to illustrate what people actually feel. One's perception of temperature is subjective, varying based on their activity and individual heat perception, influenced by factors like wind, clothing, and metabolic variations. Exposure to direct sun rays can influence the heat you feel, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. Juveniles often do not understand the need to recuperate and rehydrate. Thirst is a delayed symptom of dehydration - hence, it is vital to maintain hydration, particularly during ongoing physical activities.

Humidity

The average relative humidity in September in Umatac is 77%.

Rainfall

The month with the most rainfall in Umatac is September, when the rain falls for 28.1 days and typically aggregates up to 10.28" (261mm) of precipitation.

Daylight

In September, the average length of the day in Umatac is 12h and 13min.
On the first day of the month, sunrise is at 6:10 am and sunset at 6:32 pm. On the last day of September, sunrise is at 6:10 am and sunset at 6:11 pm ChST.

Sunshine

In Umatac, Guam, the average sunshine in September is 7.9h.

UV index

September is the month with the lowest UV index in Umatac, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for the average person.
Note: The maximum daily UV index, 6 in September, converts into the following recommendations:
Avert overexposure. Light-skinned people might experience burning in less than 20 minutes. Seek shade and limit direct Sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its peak, but be aware that not all shade structures provide complete sun protection. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
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Frequently asked questions

Is it hot in Umatac during September?

In Umatac, in September, the average high-temperature is 84.4°F (29.1°C), and the average low-temperature is 82.8°F (28.2°C). The average heat index (a.k.a. 'felt air temperature', 'feels like'), which calculates the temperature value influenced by the moisture in the air, in September is computed to be 93.2°F (34°C).

What is the average humidity in September in Umatac?

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

What is the wettest month in Umatac?

The month with the most rainfall in Umatac, Guam, is September, when the rain falls for 28.1 days and typically aggregates up to 10.28" (261mm) of precipitation.

How much does it rain in Umatac in September?

In September, in Umatac, the rain falls for 28.1 days. Throughout September, 10.28" (261mm) of precipitation is accumulated.

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

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

When is the sunrise / sunset in September in Umatac?

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

How long on average sun shines in September in Umatac?

In Umatac, Guam, the average sunshine duration in September is 7.9h.

When is the lowest UV index in Umatac?

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

What is the UV index reading in September in Umatac?

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

Average temperature in September
Umatac, GU

Average temperature in September - Umatac, 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
Umatac, GU

Average pressure in September - Umatac, 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
Umatac, GU

Average wind speed in September - Umatac, 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
Umatac, GU

Average humidity in September - Umatac, 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
Umatac, GU

Average rainfall in September - Umatac, 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
Umatac, GU

Average rainfall days in September - Umatac, 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 daylight in September /
Average sunshine in September
Umatac, GU

Average daylight in September / Average sunshine in September - Umatac, 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 24min).

  • 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
Umatac, GU

Average sunshine days in September - Umatac, 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
Umatac, GU

Average UV index in September - Umatac, 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
Umatac, GU

Average cloud cover in September - Umatac, 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
Umatac, GU

Average visibility in September - Umatac, 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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Umatac, Guam, USA

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