Wind speeds hit 76mph on the Isles of Scilly as Storm Callum blew in during the early hours of Friday.
Twenty-one Aer Lingus flights scheduled to travel to and from Dublin airport today were also cancelled.
Waves crashing over the sea wall at Saltcoats meant trains were cancelled between Kilwinning and Largs/Ardrossan. There are limited replacement buses but road closures are also likely.
In Galway city, coastal routes along the harbour are closed as a precaution ahead of high tide at around 7.45am. National Rail has recommended passengers in western parts of the United Kingdom check before they travel.
Passengers are advised to check service updates with ferry companies before travelling from either Holyhead or Fishguard.
ESB's Senior Press Officer Paul Hand said thousands of homes and businesses are without power due to damage to power lines.
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England enters having lost its only UEFA Nations League bout, falling to Spain 2-1. "It was a tough game, as we expected". Croatia were unsuccessful in their quest to win the World Cup, losing to France in the Final.
The forecast deluge poses a risk of communities being cut off by flooding, while high winds are expected to cause disruption across western areas of the UK.
Parts of the south and east escaped completely with dry conditions and temperatures in the mid-20s, with Donna Nook in Lincolnshire reaching 26.5C, making it the warmest October day in seven years, the Met Office said.
There are no reported power outages across the county - as well as no major obstructions or debris reported across the road network.
Numerous warnings are for South Wales, with people being urged to stay alert as downpours could mean river levels continuing to rise. "That's quite a substantial amount of rain to come and could bring flooding".
A 36-hour amber warning for Wales has been issued where almost a month's rain could fall over 48 hours.
"In addition, these winds may increase autumnal leaf fall, which would increase the potential for blocked drains and culverts, heightening the flooding risk".
An amber warning for rain remains in place for parts of south Wales until 6pm, with further flooding and power cuts likely.