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September Weather in Belfast, South Africa

Last updated: August 31, 2025

In September, the average temperature in Belfast, South Africa is a pleasant 16°C (60°F). Expect fluctuations, with minimums dipping to -1°C (31°F) and maximums soaring up to 31°C (88°F). This month also brings about 15 mm (0.6 in) of precipitation over 3 days, alongside an average humidity level of 65%.

September Temperature in Belfast

In September in Belfast, the weather is quite variable, making it an interesting time to visit with mild temperatures suitable for outdoor activities.

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

The chart illustrates September temperature patterns in Belfast, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Belfast, September typically has an average temperature of 16°C (60°F), with highs reaching up to 31°C (88°F) and lows dropping to around -1°C (31°F).
JanFebMarAprMayJunJulAugSepOctNovDec656563595449495560616465
Data source: Temperature data for Belfast 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 Belfast

In Belfast in September, the precipitation amount is 15 mm (0.6 in) over the course of 3 days.

September Precipitation Trends in Belfast

The chart displays monthly precipitation patterns in Belfast, 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 Belfast, September typically receives around 15 mm (0.6 inches) of precipitation spread over approximately 3 days.
JanFebMarAprMayJunJulAugSepOctNovDec120132605920513156592158
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Belfast

In Belfast in September, humidity is 65%. With an average temperature of 16°C (60°F), this humidity feels like a gentle blanket wrapping around you, making outdoor activities feel both refreshing and slightly heavy, perfect for leisurely strolls but perhaps a bit uncomfortable for rigorous exploration.

September Average Humidity in Belfast

This chart illustrates the average monthly humidity levels in Belfast, 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 Belfast is approximately 65%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec70%65%64%64%65%61%64%61%65%61%68%72%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Belfast

In Belfast in September, the maximum UV index reaches 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, you can check the Hourly UV Index in Belfast.

Maximum UV Index Levels in Belfast for September

The chart shows the monthly maximum UV Index (UVI) for Belfast 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 Belfast typically reaches 11, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec16161310867911131416
Data source: Belfast 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 Belfast Compares to Other Months

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

This table compares monthly weather conditions in Belfast, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather18°C (65°F)120 mm (4.7 inches)70%extreme
February Weather18°C (65°F)132 mm (5.2 inches)65%extreme
March Weather17°C (63°F)60 mm (2.3 inches)64%extreme
April Weather15°C (59°F)59 mm (2.3 inches)63%very high
May Weather12°C (54°F)20 mm (0.8 inches)64%very high
June Weather9°C (49°F)5 mm (0.2 inches)61%high
July Weather9°C (49°F)1 mm (0.1 inches)64%high
August Weather13°C (55°F)3 mm (0.1 inches)61%very high
September Weather16°C (60°F)15 mm (0.6 inches)65%extreme
October Weather16°C (62°F)65 mm (2.6 inches)61%extreme
November Weather18°C (64°F)92 mm (3.6 inches)68%extreme
December Weather18°C (65°F)158 mm (6.2 inches)72%extreme

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