At 11pm, it started to rain.

But dozens of homeless Canberrans do something similar every night, often in freezing temperatures or hostile environments.

On Friday night, more than 600 people packed the AIS Track and Field arena for the second annual Canberra Community SleepOut, raising money for ACT charities St Vincent de Paul and Communities@Work.

By the end of the night, more than $100,000 was raised which went towards helping people without homes who are sleeping rough or living in community housing.

Families with children laid out their sleeping mats beside groups of friends unpacking chips and cans of coke, while large groups of schoolkids vied for space.

It wasn't all harsh reality - there was a bouncy castle for the kids, free tea and coffee and breakfast and dinner provided, at a price, by the local Rotary Club.

Balls, frisbies, jumping ropes and lantern-making classes were also provided to keep the children entertained.

Bonython residents Paul Skidmore and Tanya Taylor had set up camp with their two children Nathan, 13, and Jayden, 11,  very early in the afternoon, claiming a quiet spot well away from the school groups.

"It's something that I feel strongly about particularly in Canberra in winter. It comes to the front of my mind when we complain about the cold and I think about the fact there are actually people who have to sleep and live rough," Ms Taylor said.

Ms Taylor said she wanted to show the boys how lucky the family was in the larger scheme of things.

"Even this is pretty cushy for us," she laughed.

Mr Skidmore said he had been surprised to hear a large number of homeless men and women were ex-defence force personnel. "I was surprised that people who fight for the country come back and end up in that situation," he said.

Among the families were groups of dedicated fundraisers - the most successful team on the night, Doing It For Kurt, was formed in honour of former ACT political staffer Kurt Steel, who died in Bolivia earlier this year at the age of 25.

The 11-member team, including Kurt's father Philip, raised more than $9500 for the ACT's homeless population.

"Kurt was a true believer in Canberra as a place and he was always trying to work towards making Canberra a great place, through his work in politics and in general," team member Alice Boyd said.

"He would have continued through his life to do this sort of thing, make Canberra a better place... It was just something he was very passionate about."

Banks resident Carley Bolas celebrated her 33rd birthday at the sleepout with her friends in the Ainslie Group, who together raised $5500 for charity.

She said it was great to spend her birthday with good friends for a good cause. "It was really nice to do. I don't usually do stuff for my birthday so this is great," Ms Bolas said.

Canberra and Goulburn St Vincent de Paul Society president Frank Brassil was among those who braved the oval at the AIS on Friday night, sleeping on his pink yoga mat.

There had been a brilliant response from the community, he said.

"It arose because we'd been having the CEO Sleepout and we had people saying we want to do this too, [so] this is an opportunity to extend the event to the broader community and we think it's getting a really positive response," he said.

Mr Brassil said the event had two main purposes - to raise awareness of the plight of Canberra's homeless people and to raise money to support them.

A number of well-known Canberrans joined in for the event, including ABC breakfast presenter Philip Clarke who was also master-of-ceremonies during the formal part of the evening.

After dinner, two Canberrans spoke about their experience of homelessness - a packed crowd of rowdy schoolkids and tired adults fell deadly silent as Kylie Ofiu and Anthony O'Hara recounted emotionally what it was like to feel as though  the world had turned its back on you.

Anthony broke down as he spoke of the joy at entering St Vincent de Paul's Samaritan House Men's Shelter in Hackett.

"It felt like the reason they were there was to help me and it was the first time in a very long time I felt like someone cared if I was there," he said.

After a moment's silence for the homeless Canberrans, the campers retired to their sleeping bags, blankets and swags and settled in for the night, apart from some impromptu glowstick light displays from the school groups.

There was a minor panic at 11pm when rain began to fall across the site but it cleared quickly and, apart from some brief, cheeky sprinkles, it stayed away for the rest of the night.

In the morning, those who made it through the night were woken loudly at 5am by blaring lights, loud wake-up announcements from organisers and, thankfully, the smell of brewing coffee.

Sounding surprisingly chirpy for 6am, Mr Brassil said the event had been a big success and a lot more comfortable than the CEO Sleepout.

"I got a good four hours' sleep ... we did the CEO Sleepout in Civic Square, where it got down to three degrees," he said.

As the catering groups began offering a round of bacon and egg rolls and much-needed cups of coffee, the announcement came through that overnight the $100,000 fundraising target had been reached.

Attendees headed off into the dim, pre-dawn light, remembering the words of Communities@Work chief executive officer Lynne Harwood from her speech on Friday night.

"Anne Frank said: 'How wonderful it is that nobody need wait a single moment before starting to improve the world'."