From roving entertainers, champagne, avant-garde hair stylists, "word art" and much-loved bands that have reformed especially for the centenary, the day will feel a lot like an erudite, eclectic music festival.

Event director Geoff Cobham said the day's events, which kick off at midday and run seamlessly for the next 11 hours, would evolve like a type of symphony, with the lake as the orchestra.

Just don't speculate on the weather, he said.

"Opening night is opening night, so everything has to be ready. Thousands of people are involved, both working and performing - the community groups alone are close to 1000," he said.

"The day is about turning [the centenary] inside out and bringing it all together - all the groups will be represented on the day. We've been planning it for two years, so it's very multi-faceted."

Although it's difficult to calculate crowd numbers, he said about 150,000 people were expected to flock to the lake for the festivities.

The public holiday celebrations will be focused around Lake Burley Griffin, with free buses and a ferry service across the lake.

Mr Cobham said festivals of this size usually involved a degree of outsourcing, but custom-making your own event, as the centenary team had done, was unusual.

But, having worked as production manager for nearly 30 years on big events such as the Adelaide and Sydney festivals, Canberra's birthday is all in a day's work.

And although it most definitely would not rain on the day (we hope), he admitted to have been monitoring weather forecasts for weeks. "They mean nothing," he said.

"We pull off the impossible all the time - it's no use spending too much time worrying about the event."

He said he usually ran these events with a "solution focus", and concentrated on getting more things right than wrong.

But having worked on epic, two-week festivals for many years, the one-off, decentralised nature of the birthday bash was refreshing.

"This is quite nice because it's only one day," he said.

"Robyn has empowered us to be Canberra-focused. It's normally about being as spectacular as we can be, and this is spectacular, but it's through connections with people.

''It's like a personal experience en masse."

Creative director Robyn Archer said although the Canberra Day long weekend was traditionally an opportunity to head out of town, there would be plenty of reasons to stick around for the birthday bash.

"This day will be a highly original and wholly participatory event for all Canberrans, and we want you all to be there," she said.

The entire weekend would be worth being here for, with the Enlighten Festival, the Famous Spiegel Garden and various major exhibitions at the cultural institutions, as well as an AFL match (GWS v Essendon), the Brumbies against the Waratahs in a rugby clash, and the Black Opal Stakes at Canberra Racecourse.

A full list for the day will be available on the centenary website from next week.