The Night of the Big Wind (Irish: Oíche na Gaoithe Móire), a powerful European windstorm sweeps without warning across Ireland beginning in the afternoon of January 6, 1839, causing severe damage to property and several hundred deaths. As many as one quarter of the houses in north Dublin are damaged or destroyed and 42 ships are wrecked. The storm tracks eastward to the north of Ireland bringing winds gusts of over 100 knots to the south before moving across the north of England and onto the European continent where it eventually dies out. At the time, it is the most damaging Irish storm in 300 years.
The storm develops after a period of unusual weather. Heavy snow, which is rare in Ireland, falls across the country on the night of January 5, and is replaced on the morning of January 6 by an Atlantic warm front, which brings a period of complete calm with dense, motionless, cloud cover. Through the day, temperatures rise well above their seasonal average, resulting in rapid melting of the snow.
Later in the day, a deep Atlantic depression begins to move towards Ireland, forming a cold front bringing strong winds and heavy rain when it collides with the warm air over land. First reports of stormy weather come from western County Mayo around noon and the storm moves very slowly across the island through the remainder of the day, gathering strength as it progresses.
By midnight the winds reach hurricane force. It is estimated that between 250 and 300 people lose their lives in the storm. Severe property damage is caused, particularly in Connacht, but also in Ulster and northern Leinster. Much of the inland damage is caused by a storm surge that draws large quantities of sea water inland, resulting in widespread flooding.
The Night of the Big Wind has become part of Irish folk tradition. Irish folklore held that Judgement Day would occur on the Feast of the Epiphany, January 6. Such a severe storm led many to believe that the end of the world was at hand.