She used the cover of a year-long goal to run 1000km to explain her training, and despite nearly letting the cat out of the bag, she even managed to hide that her sister Jo Farmer would fly from Darwin to join them.

As 3800 runners took to Canberra's streets on the festival's second day, temperatures dropped to 10.3 degrees by 6.30am and wind gusts reached 41km/h at 7am.

Connie Mercieca, a hero to her two daughters, ran with them through chilly headwinds to reach the finish line within minutes of each other. She had wanted to run and finish the 21km half marathon for three years.

"We finished, that's all that matters, that was the goal," Connie said.

Peta, from Gungahlin, and Jo wanted to support their mum, who they said had helped them and inspired them to be better people.

"She has been through a lot, and she always helps us out," Peta said before the race.

Peta also ran to raise money for the Domestic Violence Crisis Service, which provides support she wished was there in her childhood when she and her mother experienced family violence.

"That support, if they get it as soon as possible, impacts on the rest of their lives."

Another sister, Terri Mercieca, tracked their progress from London using an app, while Jo's husband gave her words of encouragement after she hit her limits on a run she described as a "rollercoaster".

"He messaged me, 'you won't die, just keep running'," she laughed.

A brisk morning tempted some to stay in, including marathon women's winner, Port Macquarie's Kirsten Molloy.

"I'm so glad we got out of bed today," she said at the finish line.

She ran three hours and 57 seconds, had won the race previously in 2014 and wasn't expecting to repeat the result on Sunday as an injured foot had stopped her training.

Public servant John Hulin experienced the thrill of event running again when he ran the half marathon for the first time since he broke both his legs in a head-on car crash in 2010 and spent 27 weeks on crutches, followed by years of rehabilitation.

He was told he would never run again, but finished 21 kilometres already thinking about his next challenge, despite a blister he'd battled from 8 kilometres into the course.

"I had enough belief to make it," he said.

His one hour 42 minutes result was 10 minutes better than he expected, and he plans to run the full marathon next year.

Melbourne runner Dion Finocchiaro was the first man across the line in the marathon at 2:25:38, beating 1120 others as the weather forced him and two other race leaders to hold on and run as a group.

"It was the sort of weather where you don't go for time," he said.

Marine Ponton from Glenbrook was the women's winner of the half marathon at 1:18:10.

Narrabundah's Jordan Gusman won the half marathon in 1:06:33, leading 2500 entrants and backing up from winning the 5km run on Saturday, while Newcastle runner Vlad Shatrov beat a field of 200 to win the ultra marathon with 3:05:12, preparing for the 91km Comrades Marathon in two months.

"There's only so many times you're going to win a big race in your life. Every win is special," he said.

About 7000 people entered the two-day festival's events at the weekend.