About Roscommon, Connacht's Climate & Weather History

With a population of around 5,700, Roscommon sits in Connacht, Ireland. The city operates in the GMT/IST time zone.

In 2025, Roscommon recorded an average annual temperature of 51°F. The hottest temperatures reached 85°F in July; the coolest were 26°F in January. Total precipitation for the year was 45 inches, with the wettest month being November. Snowfall for the year totaled approximately 2 inches.