Home / Editor's Pick /

On this day in 2020: Storm Dennis hit the UK and Ireland

17:00
15 February 2025

On this day in 2020
Storm Dennis hit the UK and Ireland

Large wavesLarge crashing waves at the harbour of Porthcawl, Wales provided spectacular sights for locals. - © picture alliance

On this day in 2020, Storm Dennis impacted the UK and Ireland, becoming one of the most damaging weather events in years.

Amid the two days the storm lasted over land on February 15th and 16th, Dennis delivered heavy rains and strong winds resulting in flooding across the entirety of the UK, just weeks after Storm Ciara.

At the River Taff and Rhondda catchments in Wales, more than 160 mm of rain was recorded in a day, greater than their monthly rainfall average.

A weather station in Aberdaron also recorded wind gusts as strong as 91 mph, while 50 mph gusts were also recorded in Kent.

Major incidents were declared across England, while south Wales experienced devastating flooding. At Dennis' peak, 152 flood warnings were in effect across Wales, the highest number ever in force at one time.

River levels also rose to record highs, with the River Taff at Pontypridd reaching its highest level for over 40 years, 80 cm higher than the historic flooding of 1979.

In total, seven lives were known to have been lost as a result of Storm Dennis, with five in the UK.

Ireland largely avoided widespread damage from flooding, instead experiencing fierce gale-force winds leading to widespread power outages.

Dennis was named on February 11th 2020, while still situated over southern America. As the storm moved over the Atlantic it experienced explosive intensification, becoming one of the most intense extratropical cyclones on record.

By February 17th, Dennis had moved on from the UK and impacted Europe before dissipating a day later.

Ryan Hathaway
More on the topic
Shooting star shower
Tuesday 12 August 2025

Perseids overhead

Meteor shower reaches its peak
Two-part map of Europe showing temperature distribution: on the left, high temperatures above 30°C in France, Germany and Italy; on the right, significantly cooler with temperatures below 20°C in London, Brussels and Amsterdam. A white arrow between the maps marks the change in temperature.
Tuesday 19 August 2025

High summer bids farewell

Temperature changes in Europe
Dark sky full of stars. Several shooting stars fly in different directions – typical of a meteor shower.
Thursday 14 August 2025

Photos from across Europe

Night sky in the spotlight
All weather news
This might also interest you
Weather map showing England, Wales, and south-east Ireland. Clear skies over England and Wales with Ireland overcast. A large sun icon rests over England.
Friday 8 August 2025

Clouds part

Sunny weekend ahead
Friday 15 August 2025

Breakfast brief

Split with cooler north, hot south
Tuesday 12 August 2025

Breakfast brief

Heat reaches a peak as clouds clear
All articles
Weather & Radar

www.weatherandradar.ie

facebooktwitteryouTubeContact uslinkList
Privacy Policy | Legal info | Accessibility statement