Wind gusts exceeded 180 km/h recorded in Ireland and a ‘major incident’ was declared on the Isle of Man, in the face of the devastating storm which caused extensive damage across the islands and severely hampered mobile communications.

According to Ookla, Storm Éowyn triggered a rapid, severe and sustained decline in mobile performance across all operators in Ireland and parts of the UK, particularly Northern Ireland and Scotland, on a scale not seen before.

The storm made landfall on 24 January, and median mobile download speeds in Ireland (10.04 Mbps) were 78% lower than the preceding 7-day average of 47.43 Mbps, while median latency was 23% higher at 47.6 ms.

In Scotland and Northern Ireland, mobile download speeds at the 10th percentile — a critical metric reflecting the poorest network performance —d ropped significantly on the same day, falling by 63% to 2.19 Mbps and by 74% to 1.31 Mbps, respectively, compared to the 7-day average.

Ookla says the severe storm caused users to move in significant numbers to the Starlink satellite service.

"A 62% surge in Speedtests conducted on Starlink connections in Ireland on the storm day, compared to the preceding 7-day average, highlight the severity of the telecoms infrastructure disruptions as consumers scrambled to troubleshoot issues and turned to alternative connectivity solutions like satellite," says Ookla in its announcement.

"The unprecedented scale of impact on telecoms infrastructure serves as the latest and most high-profile call to action for hardening networks against increasingly frequent and severe storms in the UK and Ireland."

The extensive damage to the electricity grid in Ireland, says Ookla, has had severe knock-on effects on both fixed and mobile network infrastructure, with well over a thousand mobile sites taken offline due to disruptions to mains power and downed trees causing damage to overhead fibre cabling along roads.

In Ireland, mobile operator Eir reported that fixed broadband faults were affecting 160,000 premises, with more than 900 mobile sites knocked offline, while Vodafone said more than 10% of its mobile site footprint was affected.

Ookla says the vulnerable mobile infrastructure in Ireland and UK compares unfavourably to regions like Australia and the Nordic nations, which have implemented comprehensive policy measures to harden telecoms infrastructure.

"It is notable that the limited penetration of battery backup solutions in Ireland’s mobile site grid—typically providing only four to eight hours of power where available—stands in sharp contrast to regions like the Nordics and Australia," says Ookla.

"This shortfall has resulted in a disproportionate reliance on stationary and mobile generators in the Irish context.

"Similar to Ireland, the penetration of battery backup solutions installed at mobile sites in the UK remains limited.

"In its latest annual ‘Connected Nations‘ report, Ofcom noted that only around 20% of all mobile sites in the UK have some backup functionality at the RAN for more than 15 minutes, while only around 5% of sites are able to withstand a six-hour power loss (excluding battery backup for transmission traffic)."