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May Weather in Belfast, South Africa

Last updated: August 31, 2025

In May, the average temperature in Belfast, South Africa hovers around 12°C (54°F). Expect a chill in the air with minimum temperatures dipping to -1°C (30°F), while the mercury can soar to a comfortable 25°C (77°F) at its peak. With an average precipitation amount of 20 mm (0.8 in) spread over just 2 days, and an overall humidity level of 64%, be prepared for a mix of crisp and refreshing weather!

May Temperature in Belfast

In May in Belfast, the average temperature is 12°C (54°F). Maximums can reach 25°C (77°F), while minimums can dip as low as -1°C (30°F). This diverse temperature range makes Belfast an ideal destination for travelers seeking a mix of comfortable days and cool, crisp evenings.

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

The chart illustrates May 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, May typically has an average temperature of 12°C (54°F), with highs reaching up to 25°C (77°F) and lows dropping to around -1°C (30°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.

May Precipitation in Belfast

In Belfast in May, the precipitation amount is 20 mm (0.8 in) over the course of 2 days.

May Precipitation Trends in Belfast

The chart displays monthly precipitation patterns in Belfast, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In Belfast, May typically receives around 20 mm (0.8 inches) of precipitation spread over approximately 2 days.
JanFebMarAprMayJunJulAugSepOctNovDec120132605920513156592158
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Belfast

In Belfast in May humidity is 64%. With an average temperature of 12°C (54°F), this humidity feels like a damp chill that can make outdoor activities uncomfortable, requiring a light jacket to stay warm while exploring.

May Average Humidity in Belfast

This chart illustrates the average monthly humidity levels in Belfast, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Belfast is approximately 64%, 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 May generated using information from the Copernicus Climate Change Service.

May UV Index in Belfast

In Belfast in May, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Belfast.

Maximum UV Index Levels in Belfast for May

The chart shows the monthly maximum UV Index (UVI) for Belfast in May, 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 May, the maximum UV index in Belfast typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec16161310867911131416
Data source: Belfast May 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 May 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 May’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 May’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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