A Victoria-wide fire report issued on the afternoon of Black Saturday failed to detail the significance of the Kilmore East fire bearing down on the Kinglake region, the bushfires royal commission has heard.

Country Fire Authority chief officer Russell Rees admits the report issued from the Integrated Emergency Control Centre (IECC) at 4pm on February 7 was short on detail.

Mr Rees told the commission on Tuesday information gathering for the fire that began in Kilmore East was "very difficult" on the day.

"The information ... in respect of that fire is probably short on detail," he said.

Counsel assisting the commission, Jack Rush QC, responded: "That would be the understatement of the day, wouldn't it Mr Rees?

"If you are giving briefings between three and four o'clock in the afternoon of the seventh of February and that is the indication of the sort of information you are providing it was totally inadequate having regard to either what was known in the IECC or what ought to have been known in the IECC."

The state fire situation report showed the CFA was responsible for 95 fires, with six under control, while the Department of Sustainability and Environment (DSE) was managing 11 active fires.

Mr Rees said it was based on a summary of information gathered between 3pm and 4pm.

The report contained fire details that may have a significant impact on Victorian communities at the time of issue.

The 4pm report described the Kilmore fire as 1,000 hectares in size, and within five hours had the potential to impact on Whittlesea, where a country music festival was being held.

It also warned the community of Hidden Valley may be directly impacted.

The fire complex later ravaged communities including Kinglake, Wandong and Strathewen.

"The information ... is probably based on information over the hour beforehand," Mr Rees told the commission.

"It is obviously not the exact scenario that the fire was at 1600."

The hearing continues.

AAP