A large tree has also come down in Karabar blocking two driveways. Local SES crews are attending the scene.

Wind gusts reached 70 km/h at 2pm and air traffic told a QantasLink flight from Sydney and a Tigerair flight from Melbourne to turn around as they approached the national capital on Wednesday afternoon. 

Severe wind shear and gusting cross winds forced the planes to turn back to their departure points where they landed safely. 

Weather conditions at the airport have since improved and no other flights will be affected.

Eight trees have fallen across the ACT including one that hit a vehicle with a limb amid heavy wind gusts.

Canberra's State Emergency Services needed a chainsaw to remove the tree from the car.

It has also arrived at a Drevermann Street, Farrer home where a tree crashed over a back fence about 2pm, taking down power lines, and a Gillies Street, Curtin house where another fell in front of a garage.

The Bureau of Meteorology said a cold front brought strong westerly to northwesterly winds to the region, with a gusty southerly change expected to move up NSW's southern and central coast later on Wednesday.

Hot and dry fresh winds were forecast ahead of the cold front, bringing severe fire danger to the ACT and Queanbeyan.

The bureau predicted damaging winds averaging 60 to 70 km/h with peak gusts more than 90 km/h were possible at higher parts of the Snowy Mountains and the ACT, but said these would ease in the evening.

East of Canberra, at Charleys Forest Road, Wog Wog, firefighters were trying to control a blaze that had burnt four hectares but posed no threat to property. 

The ACT's Emergency Services Agency urged people to take extra care when walking or travelling near trees, and not to park vehicles under them as hot temperatures and strong winds continued into the afternoon.