Long lines in various parts of the country and a burst water mains in south-east London led to people being forced to abandon their attempt to reach the ballot box with the hope of returning before polling closes at 10pm.
In a sign the winter election had not put off the electorate from turning out to vote, queues of people were reported in various parts of England, particularly in London and Manchester.
Bad weather, particularly in the north of the country, had raised fears among party machines of all colours that it could depress voting numbers, forcing people to stay at home rather than cast their vote.
Early-hour queues in Scotland
People shared a string of pictures on social media of voters queuing around the block to have their say in the election.
In Scotland, James Mackenzie-Blackman, chief executive at Inverness's Eden Court Theatre, reported a queue forming at his local polling station in the Highlands as early as 7am.
"This morning, in our tiny wee village hall, in the rural Highlands of Scotland, there was a queue, at 7am," he tweeted.
There were reports of queues at polling stations in Edinburgh.
Historian Dr Gillian Jack tweeted: "We voted at 8am and there was a queue inside. Not a massive line, but way more than I've ever seen here (Edinburgh East)."
Short queues were also seen in Edinburgh North and Leith this morning on Pilrig Street.
A missing voting register led to voters being turned away from South Leith Parish Church this morning
'Election of a lifetime'
Chris Schofield said more than 70 voters were waiting in the Bermondsey and Old Southwark constituency - some of whom gave up and left during his 20-minute wait, "presumably to go to work".
"It's about 20 times busier than it was in 2017, and for the locals and Euro elections," the 27-year-old consultant said.
"Atmosphere is very London: orderly queuing and no-one is talking to each other!"
Asked why he thought there were so many queuing, Mr Schofield said: "I think it's the election of a lifetime for many of us."
Alixe Bovey reported queuing for 35 minutes in the Streatham constituency.
"In 20 years of voting in Streatham Hill, always at about this time of day, I have never encountered a queue of more than six or seven people," she tweeted.
In Bermondsey, south-east London, a burst water main caused deep flooding in the area, leading some voters to decide to leave and return later.
Local resident Graham Kings said: "I could have gone home and put Wellington boots on and waded across the flooded road to try to get in, but had to go to work and so will vote this evening."
Lines of students voting on campuses in key marginals, such as Canterbury, Kent, and the University of Exeter as well as Lincoln, is likely to have cheered Jeremy Corbyn, who benefited from the student vote two years ago.
Waits were also reported in English cities such as Cambridge, where John Walsh tweeted to say it was the "first time ever" that he had to queue to exercise his democratic right.
Many members of the public said they were encouraged by the queues, suggesting it could mean a greater turnout than in the last general election.
Total turnout at the 2017 general election was 68.8 per cent - the fourth successive election where turnout increased.
Voters unable to vote for whatever reason can return to their polling stations at any time before 10pm.
The Electoral Commission advises polling stations "can get very busy, particularly towards the end of the day", but says voters in a queue before 10pm will be entitled to apply for a ballot paper.