September weather forecast
Semarang, Indonesia

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Weather in September

September brings a slight increase in rainfall, signifying the end of the dry season in Semarang. The number of rainy days sees a noticeable increase compared to the preceding month's consistent weather pattern. While overall temperatures remain mostly steady, cloud cover begins to encroach again. Despite the transition in the weather, sea temperatures go back up to align with the warmer days. Average rainfall swings back to a higher 73mm (2.87") taking place over 20.8 days, a significant increase compared to August.

Temperature

Welcoming September, Semarang notes an average high-temperature of a still warm 27.7°C (81.9°F), nearly consistent with August's 27°C (80.6°F). September nights are marked by an average low-temperature of 19.9°C (67.8°F).

Heat index

For September, the heat index is estimated at a tropical 31°C (87.8°F). If one endures exposure and continues to be active, it might result in tiredness and heat cramps.
Evaluating the heat index requires understanding its values in the shade and with gentle winds. If exposed to direct sunlight, the heat index could climb by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', reflects the blend of air temperature and relative humidity to give a temperature impression. The effect is experienced differently by individuals, hinging on unique characteristics such as body mass, stature, and level of activity. One must note that being under the direct sun can escalate the heat's effects, with the heat index possibly rising by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. In general, younger individuals are at greater risk than adults because they tend to sweat less. Also, having a larger skin surface to body size ratio and greater heat production due to their active behavior contribute to this danger.

Humidity

With an average relative humidity of 81%, September is the least humid month in Semarang.

Rainfall

In Semarang, in September, during 20.8 rainfall days, 73mm (2.87") of precipitation is typically accumulated. In Semarang, during the entire year, the rain falls for 305 days and collects up to 2988mm (117.64") of precipitation.

Sea temperature

In September, the average sea temperature in Semarang is 28.6°C (83.5°F).
Note: Swimming, diving, and other water activities in the temperature range of 25°C (77°F) to 29°C (84.2°F) are perceived as very enjoyable and comfortable for prolonged durations.

Daylight

In September, the average length of the day is 12h and 4min.
On the first day of the month, sunrise is at 05:38 and sunset at 17:37. On the last day of September, in Semarang, sunrise is at 05:23 and sunset at 17:33 WIB.

Sunshine

In September, the average sunshine in Semarang is 8.3h.

UV index

January through December, with an average maximum UV index of 6, are months with the highest UV index. The months with the lowest UV index in Semarang are January through December, with an average maximum UV index of 6. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV rays for average individuals.
Note: The maximum daily UV index of 6 in September interprets into the following recommendations:
Beware of overexposure. Fair-skinned individuals risk burning in less than 20 minutes. 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. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Take heed! Reflections of sand and water make the Sun's UV rays stronger.

Frequently asked questions

What is the average September temperature in Semarang?

The high-temperature in Semarang during September is 27.7°C (81.9°F) and the low-temperature is 19.9°C (67.8°F). The average heat index (a.k.a. 'felt air temperature', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, in September is estimated at 31°C (87.8°F).

What is the least humid month in Semarang?

September is the least humid month in Semarang, Indonesia, with an average relative humidity of 81%.

What is the average humidity in September in Semarang?

In September, the average relative humidity in Semarang, Indonesia, is 81%.

How many days does it rain in September in Semarang?

In Semarang, during September, the rain falls for 20.8 days and regularly aggregates up to 73mm (2.87") of precipitation.

How warm is the water in September in Semarang?

In Semarang, Indonesia, in September, the average water temperature is 28.6°C (83.5°F). Water temperature between 25°C (77°F) and 29°C (84.2°F) 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 Semarang?

In Semarang, the average day length in September is 12h and 4min.

What time are sunrise and sunset in September in Semarang?

In September, on the first day of the month, sunrise is at 05:38 and sunset at 17:37. On the last day of the month, in Semarang, sunrise is at 05:23 and sunset at 17:33 WIB.

How many hours of sunshine does Semarang have in September?

The average sunshine duration in September in Semarang, Indonesia, is 8.3h.

When is the highest UV index in Semarang?

January through December, with an average maximum UV index of 6, are months with the highest UV index in Semarang, Indonesia.

What are the months with the lowest UV index in Semarang?

January through December, with an average maximum UV index of 6, are months with the lowest UV index in Semarang, Indonesia.

How high is the UV index in September in Semarang?

In September, the average daily maximum UV index is 6. A UV Index reading of 6 to 7 represents a high health threat from unsafe exposure to Sun's UV rays.

Average temperature in September
Semarang, Indonesia

Average temperature in September - Semarang, Indonesia
  • Average high temperature in September: 27.7°C

The warmest month (with the highest average high temperature) is October (27.9°C).
The month with the lowest average high temperature is July (26.7°C).

  • Average low temperature in September: 19.9°C

The months with the highest average low temperature are January and December (21.6°C).
The coldest month (with the lowest average low temperature) is August (19.4°C).

Average pressure in September
Semarang, Indonesia

Average pressure in September - Semarang, Indonesia
  • Average pressure in September: 1011.6mbar

The months with the highest atmospheric pressure are August and September (1011.6mbar).
The month with the lowest atmospheric pressure is December (1009.1mbar).

Average wind speed in September
Semarang, Indonesia

Average wind speed in September - Semarang, Indonesia
  • Average wind speed in September: 5.9km/h

The windiest months (with the highest average wind speed) are January, July, August and September (5.9km/h).
The calmest month (with the lowest average wind speed) is April (3.7km/h).

Average humidity in September
Semarang, Indonesia

Average humidity in September - Semarang, Indonesia
  • Average humidity in September: 81%

The months with the highest relative humidity are February, April and May (86%).
The month with the lowest relative humidity is September (81%).

Average rainfall in September
Semarang, Indonesia

Average rainfall in September - Semarang, Indonesia
  • Average rainfall in September: 73mm

The wettest month (with the highest rainfall) is March (404mm).
The driest month (with the least rainfall) is August (43mm).

Average rainfall days in September
Semarang, Indonesia

Average rainfall days in September - Semarang, Indonesia
  • Average rainfall days in September: 20.8 days

The month with the highest number of rainy days is January (30.1 days).
The month with the least rainy days is August (15.8 days).

Average sea temperature in September
Semarang, Indonesia

Average sea temperature in September - Semarang, Indonesia
  • Average sea temperature in September: 28.6°C

The best month for swimming (with the highest average sea temperature) is December (30.3°C).
The coldest month (with the lowest average sea temperature) is August (28°C).

Average daylight in September /
Average sunshine in September
Semarang, Indonesia

Average daylight in September / Average sunshine in September - Semarang, Indonesia
  • Average daylight in September: 12h and 1min

The month with the longest days is December (Average daylight: 12h and 30min).
The month with the shortest days is June (Average daylight: 11h and 42min).

  • Average sunshine in September: 8h and 2min

The month with the most sunshine is August (Average sunshine: 8h and 36min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).

Average sunshine days in September
Semarang, Indonesia

Average sunshine days in September - Semarang, Indonesia
  • Average sunshine days in September: 6.6 days

The month with the most sunshine days is August (11.3 days).
The month with the least sunshine days is February (0.2 days).

Average UV index in September
Semarang, Indonesia

Average UV index in September - Semarang, Indonesia
  • Average UV index in September: 6

The months with the highest UV index are January, February, March, April, May, June, July, August, September, October, November and December (UV index 6).
The months with the lowest UV index are January, February, March, April, May, June, July, August, September, October, November and December (UV index 6).

Average cloud cover in September
Semarang, Indonesia

Average cloud cover in September - Semarang, Indonesia
  • Average cloud cover in September: 40

The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 36).

Average visibility in September
Semarang, Indonesia

Average visibility in September - Semarang, Indonesia
  • Average visibility in September: 8km

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (8km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (8km).

Semarang, Indonesia

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