Dun Laoghaire Temperature by Month

Dun Laoghaire, Dublin County, Ireland has an average annual maximum temperature of 14°C (57°F), with moderate seasonal shifts ranging from 9°C (48°F) in January to 19°C (66°F) in July. Below you'll find a full monthly breakdown and a comparison with cities worldwide.

In Dun Laoghaire, seasonal changes bring about a moderate variation in temperatures. Nighttime lows range from 13°C (55°F) in July to 4°C (39°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in Dun Laoghaire by month:

Temperatures tend to bottom out between 4 AM and 6 AM, then climb to their daily peak around 3 PM. July, the warmest month, sees 166 hours of sunshine.

The chart below shows the average temperature throughout the year:

Dun Laoghaire's average annual maximum temperature is 14°C (57°F). To put that in context, here's how it compares to a few well-known destinations:

Seville, Spain averages 23°C (73°F) a year, one of the warmer cities in Western Europe, with long hot summers.

Reykjavík, Iceland averages 9°C (48°F) a year, mild summers by Icelandic standards, but cold winters and frequent wind.

Buenos Aires, Argentina averages 23°C (73°F) a year, with hot summers and mild winters, and seasons reversed compared to Europe.

Tokyo, Japan averages 21°C (70°F) a year, with hot summers, cool winters, and a well-defined cherry blossom spring.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.

In Dun Laoghaire, January is the coolest month, with average highs of 9°C (48°F) and humidity around 81%, considered very high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained, so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.

For more on Dun Laoghaire's weather, including monthly rainfall, sunshine hours, and humidity, visit our Dun Laoghaire climate page.