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September Weather in Sia, Vietnam

Last updated: August 28, 2025

In Sia, Vietnam, the average temperature in September is a warm 28°C (83°F). Expect minimums of 23°C (74°F) and the heat peaking at 35°C (96°F). With a significant precipitation amount of 274 mm (10.8 in) over 23 days, the atmosphere remains quite lush, resulting in an average humidity of 87%.

September Temperature in Sia

In September in Sia, the average temperature is 28°C (83°F). Maximum temperatures can reach 35°C (96°F), while the minimum can dip down to 23°C (74°F). This pleasant climate makes it an ideal time for outdoor activities and exploration.

September Weather in Sia: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Sia, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Sia, September typically has an average temperature of 28°C (83°F), with highs reaching up to 35°C (96°F) and lows dropping to around 23°C (74°F).
JanFebMarAprMayJunJulAugSepOctNovDec717277798386868683797672
Data source: Temperature data for Sia generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Sia

In Sia in September, the precipitation amount is 274 mm (10.8 in) over a span of 23 days.

September Precipitation Trends in Sia

The chart displays monthly precipitation patterns in Sia, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Sia, September typically receives around 274 mm (10.8 inches) of precipitation spread over approximately 23 days.
JanFebMarAprMayJunJulAugSepOctNovDec1819681132175146220189274585605351
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Sia

In Sia in September humidity is 87%. With an average temperature of 28°C (83°F), this humidity feels like you're enveloped in a warm, sticky blanket, making outdoor activities slightly uncomfortable and travel plans require frequent breaks for hydration and respite from the heat.

September Average Humidity in Sia

This chart illustrates the average monthly humidity levels in Sia, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Sia is approximately 87%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec77%73%64%60%73%82%90%92%87%85%84%83%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Sia

In Sia in September, the maximum UV index reaches 13, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's crucial to take protective measures. For detailed information, you can check the Hourly UV Index in Sia.

Maximum UV Index Levels in Sia for September

The chart shows the monthly maximum UV Index (UVI) for Sia in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Sia typically reaches 13, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec10121314141314141312109
Data source: Sia September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How September Weather in Sia Compares to Other Months

Weather in Sia varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Sia, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Sia, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather22°C (71°F)181 mm (7.1 inches)77%very high
February Weather22°C (72°F)96 mm (3.8 inches)73%extreme
March Weather25°C (77°F)81 mm (3.2 inches)64%extreme
April Weather26°C (80°F)132 mm (5.2 inches)60%extreme
May Weather29°C (84°F)175 mm (6.9 inches)73%extreme
June Weather30°C (87°F)146 mm (5.7 inches)82%extreme
July Weather30°C (86°F)220 mm (8.7 inches)90%extreme
August Weather30°C (86°F)189 mm (7.4 inches)92%extreme
September Weather28°C (83°F)274 mm (10.8 inches)87%extreme
October Weather26°C (80°F)585 mm (23.0 inches)85%extreme
November Weather25°C (76°F)605 mm (23.8 inches)84%very high
December Weather22°C (72°F)351 mm (13.8 inches)83%very high

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