Dún Laoghaire weather in August
Temperature, sea and sunshine in August: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in August
Poor
Best time to visit: April – September
What is the weather like in Dún Laoghaire in August?
In August, Dún Laoghaire is mild: daytime highs average 18 °C, and nights cool down to about 13 °C. The sea averages 15.3 °C – swimming is only for the hardy. Expect around 5 hours of sunshine a day. Rain is frequent, with about 13 rainy days and 73 mm in total. All in all, August is not an ideal month for a holiday in Dún Laoghaire.
August compared
How the weather changes from July to September. Tap a month to open it.
| JulyJul | AugustAug | SeptemberSep | |
|---|---|---|---|
| Score | 12 | 14 | 13 |
| Day | 18° | 18° | 17° |
| Night | 13° | 13° | 12° |
| Sea | 15° | 15° | 15° |
| Sun | 5 h | 5 h | 4 h |
| Rain days | 14 | 13 | 12 |
More details for August
- Daylight
- 14 h 52 min06:03 – 20:56
- UV index
- 5 · moderateclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 20 km/haverage daily peakAll months
- Cloud cover
- 74 %on averageAll months
- Hot days
- 0 days30 °C or more
- Snow days
- 0 days1 cm or more of fresh snow
- Time zone
- UTC+1Europe/Dublin
How the score comes together
- Temperatureweight 35 %0 %
- Seaweight 25 %0 %
- Sunshineweight 20 %32 %
- Few rainy daysweight 20 %38 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Sun, sea & sand”.
What to pack in August
- Sunscreen
- A jumper for the evenings
- Rain jacket or umbrella
Dún Laoghaire in August: quick answers
Is Dún Laoghaire hot in August?
No. In August, Dún Laoghaire is mild: daytime highs average 18 °C and nights drop to about 13 °C.
Can you swim in Dún Laoghaire in August?
Only if you don't mind cold water: in August the sea averages just 15.3 °C. Comfortable swimming temperatures are not reached at any time of year.
Does it rain much in Dún Laoghaire in August?
Rain is frequent, with about 13 rainy days and 73 mm in total.
Dún Laoghaire month by month
The whole year in Dún LaoghaireAll destinations: IrelandWhere to go in AugustSea temperature in August
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences