Portmarnock is a city of approximately 9,300 people in Leinster, Ireland. Located in the GMT/IST time zone at 53.4°N latitude.
In 2025, Portmarnock recorded an average annual temperature of 53°F. The hottest temperatures reached 80°F in July; the coolest were 27°F in January. Total precipitation for the year was 46 inches, with the wettest month being September. Snowfall for the year totaled approximately 1 inches.
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