Canberra weather: Showers and severe thunderstorm warning issued for the ACT

The Bureau of Meteorology put out a severe warning at 5.03pm saying severe thunderstorms moving over northern parts of the region could result in heavy rainfall.

At least 20 millimetres of rainfall was recorded at Canberra Airport by 8.30pm, most of which fell in under an hour, while 17 millimetres fell at Tuggeranong.

The wet weather led to at least one accident on the region's roads.

Heavy traffic collected on the Monaro Highway at Hume after a car and a motorbike collided in the southbound lane. No significant injuries were reported. An ESA spokeswoman expected traffic to begin clearing shortly after 6pm.

The State Emergency Service has advised Canberrans to keep clear of creeks and storm drains, unplug computers and appliances, avoid using their phone during the storm.

"Stay indoors away from windows, and keep children and pets indoors as well," the SES said.

People have been asked not to travel through flood water and if trapped, to seek refuge at the highest place available and ring 000 if they need a rescue.

After a warm and sunny weekend, this week's forecasts includes a "lengthy period of unsettled weather conditions" with showers and thunderstorms.

A maximum of 26 degrees is forecast on Wednesday with a maximum of 24 expected on Thursday.

Bureau meteorologist Jiwon Park said the wet weather was being caused by an inland trough moving into the ACT from western NSW.

"There may be a break in the wet conditions on Thursday and Friday but we're expecting showers to resume on the weekend as the trough moves further west," Mr Park said.

READ MORE:

A maximum of 23 is forecast on Saturday with medium chance of showers. There is a high chance of showers in forecast on Sunday with a maximum of 23.

Rainfall for October was well below average. Total rainfall for Canberra during October was 32.6mm, which was 58 per cent of the long-term October average of 55.9mm.

The Bureau said there was an 80 per cent chance of maximum temperatures from December to February being higher than last year in the ACT and for much of NSW.

Bureau of Meteorology's Canberra forecast: