A a return to hot conditions and the arrival of strong winds have prompted a total fire ban to be declared across the ACT and much of NSW from midnight Monday.
Tuesday's temperature is expected to hit 31 degrees.
The total fire ban is in place as a result of the combination of gusty wind conditions and low humidity, which means that if a fire starts, it may become uncontrollable and move quickly.
NSW rural fire authorities have described Tuesday's conditions across the state as creating the worst fire danger of the summer, with extreme conditions predicted across the Greater Hunter.
In the ACT the forecast fire danger rating is severe, which ranks alongside the worst conditions seen this summer.
A hot air mass is moving across NSW and the ACT on Tuesday ahead of the passage of a cold front, which is expected to bring relief by Wednesday.
A spokesperson for ACT's fire services said the customary fire ban restrictions would be in place on Tuesday, and additional fire crews would be stood up as a precaution. All four of the ACT's remote fire towers would be crewed from 10am.
The Bureau of Meterology is forecasting that winds will increase to an average of between 50km/h to 60km/h by late morning on Tuesday and there is the potential for damaging gusts in excess of 90km/h across the territory.
As the front passes through during Tuesday evening, the hot westerly winds will turn more south-westerly and conditions will gradually cool off. A maximum of 24 degrees is forecast for Wednesday.
- Light, maintain or use a fire in the open air;
- Use fireworks in the open air;
- Undertake a high risk activity. These are activities which may cause fire to ignite, and include welding, grinding, soldering and gas cutting; and
- Use of slashers and harvesting machinery in rural areas.