A memorial is being unveiled for Jo Cox later and a choir will sing in Birstall town centre to mark a year since the MP's murder.
The event has been organised by her sister, Kim Leadbeater, and comes as school assemblies, street parties and picnics are held around the country this weekend to honour her.
Mrs Cox who was a vocal campaigner for Syrian refugees and for Britain to stay in the EU, was shot and stabbed to death by far-right extremist Thomas Mair, who is now serving a whole-life term.
The Jo Cox Foundation, a charity set up by her widower Brendan with money donated following her murder, has been concentrating on spreading her message of unity.
In her maiden speech in the House of Commons in June 2015, she said: "We are far more united and have far more in common with each other than things that divide us."
Remembering the brave, humane, generous Jo Cox today. Sending love to Brendan, his children and the whole family. #MoreInCommon— Ed Miliband (@Ed_Miliband) June 16, 2017
The foundation has helped to organise this weekend's nationwide events under the banner The Great Get Together.
More than 108,000 get-togethers are happening across the country, according to the event's website, including bake-offs, barbecues and games of football.
Mr Cox told Sky News that in keeping with his wife's message of unity the idea is to "celebrate the things that bind us together".
"What moments like the London Bridge attack or the Manchester attack, or the killing of Jo do, is they shake up complacency and create a great amount of anger," he said.
"The question is how do we channel that - and I hope we channel it in a way that brings our community together [and] emphasises those things that we have in common...
"If we can awake that silent majority we can force those extremists to the margins where they belong."
The 41-year-old mother of two was killed by Mair as she arrived for her weekly surgery in her Batley and Spen constituency in West Yorkshire during the EU referendum campaign.