Dublin
Ireland
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Dublin, Ireland

A sunset view of the illuminated Ha Penny Bridge reflected in the water below, in Dublin, Ireland
A sunset view of the illuminated Ha Penny Bridge reflected in the water below, in Dublin, Ireland
September, the first month of the autumn, in Dublin, is still a comfortable month, with average temperature fluctuating between 11.4°C (52.5°F) and 17.3°C (63.1°F).

Temperature

In Dublin, the average high-temperature is practically the same as in August - a still enjoyable 17.3°C (63.1°F). In Dublin, Ireland, in September, the average low-temperature is 11.4°C (52.5°F).

Rainfall

In Dublin, in September, it is raining for 9 days, with typically 56.7mm (2.23") of accumulated precipitation. Throughout the year, in Dublin, there are 128 rainfall days, and 714.4mm (28.13") of precipitation is accumulated.

Sea temperature

In Dublin, in September, the average water temperature is 14.8°C (58.6°F).
Note: 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.

Daylight

In September, the average length of the day in Dublin is 12.7h.

Sunshine

The average sunshine in September is 4.3h.

UV index

In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from the exposure to the Sun's UV radiation for the ordinary person.
Note: In September, the average maximum UV index of 4 translate into the following recommendations:
Take precautions - Protection against the skin and eye damage is obliged. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.

What is the temperature in September in Dublin?

In Dublin, in September, the average high-temperature is 17.3°C (63.1°F), and the average low-temperature is 11.4°C (52.5°F).

How many days does it rain in September in Dublin?

In Dublin, in September, it is raining for 9 days, with typically 56.7mm (2.23") of accumulated precipitation.

What is the sea water temperature in September in Dublin?

In Dublin, in September, the average water temperature 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.

How many hours of daylight does Dublin have in September?

In September, the average length of the day in Dublin, Ireland, is 12.7h.

How long on average sun shines in September in Dublin?

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

What is the UV index reading in September in Dublin?

In Dublin, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium hazard to health from unprotected exposure to the UV radiation.
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).
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 lowest rainfall) is February (46.1mm).

Average rainfall days in September - Dublin, Ireland
  • Average rainfall days in September: 9 days

Months with the highest number of rainy days are January, October and December (12 days).
Months with the lowest number of 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: 12.7h

The month with the longest days is June (Average daylight: 16.9h).
The month with shortest days is December (Average daylight: 7.6h).

  • Average sunshine in September: 4.3h

The month with most sunshine is May (Average sunshine: 6.3h).
The month with least sunshine is December (Average sunshine: 1.7h).

Average UV index in September - Dublin, Ireland
  • Average UV index in September: 4

Months with the highest UV index are June and July (UV index 6).
Months with the lowest UV index are January and December (UV index 0).