Facts About Snowfall in Ireland

While we continue to wait for our first big snowfall of the winter season, here is some snow trivia to keep you entertained.

- Snow forms from ice crystals that are created within clouds that have a temperature of below -0.0c. These delicate crystals form when water vapour condenses directly into ice (known as ‘sublimation’) rather than from supercooled water droplets that subsequently freeze. A single snowflake consists of a number of these tiny crystals.

- Because it contains a high percentage of trapped air (between 70-95%!) falling snow or an accumulation of fresh snow absorbs sound, which may explain the sometimes perceived quietness when snow is falling.

- The air trapped between the clusters of ice crystals in fresh snow also helps to make it a good insulator, keeping ground temperatures relatively warm.

- It is never too cold to snow, but it is less likely to snow when temperatures are exceptionally low as very cold air contains very little moisture.

- It is impossible for rain to turn to snow. A raindrop will freeze into an ice pellet rather than snow if falling through a very cold layer of air.

- Generally speaking, the larger the snowflake, the warmer and more humid the air mass. When falling through a relatively warm, moist layer of air, snowflakes will partially melt on their outer layer making the easier to clump together as they descend towards the surface.

- The idea that no two snowflakes are the same is based purely on theory rather than on hard evidence.

- Broadly speaking, the water equivalent of fresh snow is around 1/10. For example, 10cm of fresh snow will have the water equivalent of around 1cm approximately.

- In Europe and North America, the biggest snowstorms tend to be associated with Occluded fronts.


- Due to its geographical location and exposure to Polar air streams, Donegal is Ireland’s snowiest county on average. In contrast, southern and southeastern coastal counties experience the least snow.

- One of the heaviest snowfalls ever recorded in Ireland occurred not in winter, but in mid-Spring, when up to 2 foot of snow fell in parts of Connacht and north Munster in the space of a few hours on the 1st April 1917.

- The winter of 1946-1947 is probably the snowiest winter on record in Ireland and although the winter of 62-63 was infamously cold, relatively little snow was recorded overall during that season.

- Although January 1982 is famed for bringing heavy snowfalls along parts of the east coast, less documented is the fact that equally heavy and disruptive snowfalls affected many parts of Ulster, Connacht and north Leinster during the previous month (December 1981)

- Based on Met Eireann data, the number of days with observed falling and lying snow in Ireland has decreased by around 10% since 1961.

Snow facts/data by Patrick Gordon (TMT)