But organisors announced on Saturday morning that both events were back open.

The cancellation fell on the capital's second wettest September on record and was the first time in the annual event's 29-year history that it had closed for an entire day or longer.

But disappointed flower lovers could have opted to visit a winter wonderland instead as snow fell south of the city.

Director of Cultural Canberra Adam Stankevicius said the wild weather had forced organisers to make the "difficult" decision to close the event on Thursday and Friday and was to protect visitors from an unsafe site.

"The safety of our patrons is our most important consideration and we have a site that is water logged and where paths are soggy," he said.

"The flowers have held up quite well as it is wind that has the biggest impact on them and that has been manageable, but in terms of large amounts of people moving around the site it would have been unsafe."

He said ACT government staff had been working tirelessly on Thursday and Friday to repair the damage and "certainly intended" to open the event on Friday based on the current weather forecast.

Ticketek had contacted ticket holders of Nightfest with an option to transfer their tickets to another night or be refunded.

Mr Stankevicius urged those intending to visit Floriade on the weekend to check local media on Saturday morning for information on its reopening.

The heavy rain overnight on Wednesday and Thursday took Canberra's official total September rainfall to 148 millimetres.

That was 2.6mm shy of the wettest September on record, set in 1978. The gauges did collect a little more rain, but after the official 9am cut off for the monthly count.

While the wet stuff bucketed down in Canberra's suburbs, the white stuff decorated Corin Forest, which reported natural snow falls of 10 centimetres overnight.

The Corin Forest Retreat was open for tobogganing and food service, but its Alpine Slide was closed.

Corin Road was also closed due to 'heavy snow' in the morning but re-opened shortly before midday.

Friday's rain had melted much of the snow at Tidbinbilla by lunchtime, but snowmen could still be seen perched on stumps around the nature reserve.

In the mountains further south, Thredbo received 25 centimetres of fresh snow up the top of the mountain and five centimetres in the village and Perisher received 12 centimetres.

David Barlow from the Bureau of Meteorology said the low pressure system that caused downpours of showers in Canberra and earlier wreaked havoc in South Australia had passed the ACT by Friday afternoon.

Canberrans keen to check out Floriade on the weekend were urged to get in fast when it re-opens, as the weather is expected to take another turn on Monday.

"There is a slight chance of a shower on Saturday morning, but it will be dry on Saturday afternoon and on Sunday," Mr Barlow said.

"On Monday there is another low pressure system approaching with a higher chance of showers."

Sunday was tipped to be the sunniest and warmest day of the long weekend with an expected top of 21 degrees, while Saturday and Monday were likely to reach 13 and 16 degrees.