September weather forecastDublin, Ireland

The illuminated Ha Penny Bridge reflected in the water below, in Dublin, Ireland

September

Weather in September

Dublin in September witnesses a gradual descent in temperature, indicating the onset of the autumn season. Yet, the sea maintains a comfortable 14.8°C (58.6°F) that blends seamlessly with the cooling air. As mildness infuses the air, the city changes hue, shrugging on the colors of fall. The days, while beginning to shorten, are still bathed in an appreciable amount of sunlight. Despite the declining temperatures, Dublin sustains its enchanting atmosphere as it embraces the seasonal transition.

Temperature

The introduction of September sees an average high-temperature of a still comfortable 17.3°C (63.1°F), hardly deviating from August. The average temperature in Dublin during September nights dips to a fresh 11.4°C (52.5°F).

Rainfall

In Dublin, during September, the rain falls for 9 days and regularly aggregates up to 57mm (2.24") of precipitation. In Dublin, during the entire year, the rain falls for 128 days and collects up to 714mm (28.11") of precipitation.

Sea temperature

In Dublin, in September, the average water temperature is 14.8°C (58.6°F).
Note: You can swim in 14.8°C (58.6°F) below 10°C (50°F) with proper thermal wear; failing that, the cold shock and respiratory challenges are nearly certain. A short span at 13°C (55.4°F) without it is tough.

Daylight

The average length of the day in September is 12h and 41min.
On the first day of the month, sunrise is at 6:35 am and sunset at 8:14 pm. On the last day of September, in Dublin, Ireland, sunrise is at 7:25 am and sunset at 7:03 pm IST.

Sunshine

In September, the average sunshine is 4.3h.

UV index

The average daily maximum UV index in September in Dublin, Ireland, is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for the average person.
Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Undertake precautions - Obligation exists to protect against skin and eye damage. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades.

Updated: Jan 27, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

The high-temperature, in September, in Dublin, is 17.3°C (63.1°F), while the low-temperature averages to 11.4°C (52.5°F).

In Dublin, in September, it is raining for 9 days, with typically 57mm (2.24") of accumulated precipitation.

In Dublin, Ireland, the average seawater temperature in September is 14.8°C (58.6°F). Swimming in 14.8°C (58.6°F) is considered life-threatening. Even a few minutes in 13°C (55.4°F) water is uncomfortable, and swimming below 10°C (50°F) may cause total loss of breathing control and cold shock, depending on a person's physique.

In Dublin, Ireland, the average day length in September is 12h and 41min.

In September, on the first day of the month, sunrise is at 6:35 am and sunset at 8:14 pm. On the last day of the month, in Dublin, Ireland, sunrise is at 7:25 am and sunset at 7:03 pm IST.

In Dublin, Ireland, the average sunshine duration in September is 4.3h.

In Dublin, Ireland, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health threat from unprotected exposure to UV radiation.

Today

Tomorrow

Long-term

Year J F M A M J J A September O N D

Aug

September

Oct

Average high temperature

19.6°C

17.3°C

14°C

Average low temperature

Average rainfall

Average rainfall days

Average sea temperature

Average daylight

Average sunshine

Average UV index

Average temperature in September
Dublin, Ireland

Average high temperature in September: 17.3°C

The warmest month (with the highest average high temperature) is July (20.2°C).
The month with the lowest average high temperature is January (8.8°C).

Average low temperature in September: 11.4°C

The month with the highest average low temperature is July (13.5°C).
The coldest months (with the lowest average low temperature) are January and February (3.9°C).

Average rainfall in September
Dublin, Ireland

Average rainfall in September: 56.7mm

The wettest month (with the highest rainfall) is October (76mm).
The driest month (with the least rainfall) is February (46.1mm).

Average rainfall days in September
Dublin, Ireland

Average rainfall days in September: 9 days

The months with the highest number of rainy days are January, October and December (12 days).
The months with the least rainy days are June and September (9 days).

Average sea temperature in September
Dublin, Ireland

Average sea temperature in September: 14.8°C

The best month for swimming (with the highest average sea temperature) is August (14.9°C).
The coldest month (with the lowest average sea temperature) is March (8.4°C).

Average daylight in September /
Average sunshine in September
Dublin, Ireland

Average daylight in September: 12h and 42min

The month with the longest days is June (Average daylight: 16h and 54min).
The month with the shortest days is December (Average daylight: 7h and 36min).

Average sunshine in September: 4h and 18min

The month with the most sunshine is May (Average sunshine: 6h and 18min).
The month with the least sunshine is December (Average sunshine: 1h and 42min).