Canberra's temperature soared past 40 degrees on Saturday afternoon but higher humidity was proving beneficial in slowing the spread of bushfires in the region.
Canberra hit a top temperature of 42 degrees at 2.22pm and wind gusts reached 61km/hr.
Bureau of Meteorology forecaster Neil Bennett said just after 3pm the ACT was sitting at 41.2 degrees. That temperature wasn't expected to fall too much over the afternoon and into the late evening.
The winds had died down to about 35km/hr by about 3pm, but there was potential for stronger winds up to 50km/hr into the later afternoon and evening.
"That's obviously not good for the fires," Mr Bennett said.
"The combination of the high temperatures and strong winds is why we've got the fire danger ratings that we have today."
Mr Bennett said high humidity was "holding the fires back".
"It's an inhibitor to the fire conditions, it has put a little bit of a lid on what would've been conditions two to three weeks ago," he said.
He said the issue for firefighting tomorrow was the forecast thunderstorm, and the possibility of severe conditions related to that.
"We think the worst of the fire conditions are today, but we're not really expecting to see cooler conditions moving in with a drop in the fire danger risks until Monday. The thunderstorm risk tomorrow adds to the complexity," he said.
The thunderstorm could potentially bring some localised heavy rainfall.
"There will be very difficult firefighting conditions again tomorrow," Mr Bennett said.
"There is no room for complacency."
Saturday night's minimum temperature is forecast to be 24 degrees.
The maximum on Sunday is forecast to be 35 with the overnight temperature forecast to be 15 degrees.
Monday's maximum temperature is forecast to be 30 degrees.