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September Weather in Dublin, United States

Last updated: June 24, 2025

In September, the average temperature in Dublin, United States is a pleasant 21°C (70°F). However, temperatures can vary significantly, dipping as low as 5°C (42°F) and soaring to a maximum of 34°C (94°F). Visitors should be prepared for a fair share of rain, with an average precipitation of 96 mm (3.8 in) over 10 days. Additionally, the average humidity hovers around 66%, creating a mild and enjoyable climate.

September Temperature in Dublin

In September in Dublin, the average temperature is 21°C (70°F), with maximums reaching up to 34°C (94°F) and minimums dropping as low as 5°C (42°F). This makes it an ideal time for travelers who enjoy warm weather but should also be prepared for cooler evenings.

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

The chart illustrates September temperature patterns in Dublin, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Dublin, September typically has an average temperature of 21°C (70°F), with highs reaching up to 34°C (94°F) and lows dropping to around 5°C (42°F).
JanFebMarAprMayJunJulAugSepOctNovDec343743536372787570604538
Data source: Temperature data for Dublin 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 Dublin

In Dublin in September, the total precipitation amount is 96 mm (3.8 in) over a span of 10 days.

September Precipitation Trends in Dublin

The chart displays monthly precipitation patterns in Dublin, 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 Dublin, September typically receives around 96 mm (3.8 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec671081081051441041481559610584102
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Dublin

In Dublin in September humidity is 66%. With an average temperature of 21°C (70°F), this humidity feels like a warm embrace, making it comfortable for leisurely strolls but slightly sticky for longer excursions.

September Average Humidity in Dublin

This chart illustrates the average monthly humidity levels in Dublin, 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 Dublin is approximately 66%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%85%85%83%75%74%65%62%66%79%87%85%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Dublin

In Dublin in September, 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 Dublin.

Maximum UV Index Levels in Dublin for September

The chart shows the monthly maximum UV Index (UVI) for Dublin 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 Dublin typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec356810101098642
Data source: Dublin 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 Dublin Compares to Other Months

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

This table compares monthly weather conditions in Dublin, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather1°C (34°F)67 mm (2.6 inches)87%moderate
February Weather3°C (37°F)108 mm (4.3 inches)85%moderate
March Weather6°C (43°F)108 mm (4.3 inches)85%high
April Weather12°C (53°F)105 mm (4.1 inches)83%very high
May Weather17°C (63°F)144 mm (5.7 inches)75%very high
June Weather22°C (72°F)104 mm (4.1 inches)73%very high
July Weather25°C (78°F)148 mm (5.8 inches)65%very high
August Weather24°C (75°F)155 mm (6.1 inches)62%very high
September Weather21°C (70°F)96 mm (3.8 inches)66%very high
October Weather15°C (60°F)105 mm (4.2 inches)79%high
November Weather7°C (45°F)84 mm (3.3 inches)87%moderate
December Weather3°C (38°F)102 mm (4.0 inches)85%low

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