Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The advent of September denotes an average high-temperature of a still warm 84.4°F (29.1°C), subtly different from August's 84.7°F (29.3°C). Throughout September, Dededo's nights experience a slight temperature dip to a still moderately hot 82.8°F (28.2°C).Heat index
The heat index for September is calculated to be a hot 93.2°F (34°C). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.For clarity, heat index numbers account for light winds and areas under shade. Being exposed to direct sunshine might trigger a heat index increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'real feel', gives an indication of how one might feel in terms of heat after considering humidity. A person's impression of weather can be shaped by several aspects, among them metabolic variations, pregnancy, and levels of physical activity. Direct exposure to the sun's rays can enhance the felt temperature, increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Children often overlook the need for breaks and fluid intake. Thirst is a late-stage sign of dehydration - hence, it is necessary to stay hydrated, especially during extended periods of physical activities.
Humidity
The average relative humidity in September is 77%.Rainfall
September is the month with the most rainfall. Rain falls for 28.1 days and accumulates 10.28" (261mm) of precipitation.Daylight
In Dededo, Guam, the average length of the day in September is 12h and 13min.On the first day of the month, sunrise is at 6:09 am and sunset at 6:31 pm. On the last day of September, sunrise is at 6:09 am and sunset at 6:11 pm ChST.
Sunshine
In September, the average sunshine in Dededo is 7.9h.UV index
The month with the lowest UV index is September, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high health hazard from unsafe exposure to UV radiation for the ordinary person.Note: In September, a regular UV index of 6 translates into these guidelines:
Take precautions and utilize sun safety practices. Protection against skin and eye damage is required. Avoid exposure to the Sun and try to stay in the shade between 10 a.m. and 4 p.m., when UV radiation is most potent, but be aware that parasols or canopies may not offer full protection. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot does it get in September?
What is the average humidity in September?
What is the rainiest month?
How much does it rain in September?
How many hours of daylight does Dededo have in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the month with the lowest UV index?
What is the UV index reading in September?
Average temperature in September
Dededo, 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).
Average pressure in September
Dededo, 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).
Average wind speed in September
Dededo, 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).
Average humidity in September
Dededo, 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%).
Average rainfall in September
Dededo, 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").
Average rainfall days in September
Dededo, 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).
Average daylight in September /
Average sunshine in September
Dededo, 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).
Average sunshine days in September
Dededo, 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).
Average UV index in September
Dededo, 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).
Average cloud cover in September
Dededo, 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).
Average visibility in September
Dededo, 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).
Dededo, Guam, USA
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