The man's black Subaru Impreza crashed sideways into a tree at the corner of Sternberg Crescent and Houston Street about 4pm.

ACT Ambulance were called to the scene, but the man was already dead.

Sergeant Rod Anderson said the man was the only person in the car at the time and he had died on impact.

He said speed and the wet weather appeared to have been possible factors in the accident.

''It looks like a high-speed impact, but that will be determined by our crash investigation team,'' he said.

Sternberg Crescent and Houston Street remained closed until almost 9pm as police investigated the scene.

The parents of the driver had not yet been notified on Wednesday night, although some members of his family had been told.

Sergeant Anderson said ACT drivers had to remember to take care in the wet conditions forecast for the rest of the week.

''This is another reminder for people to slow down in the wet weather,'' he said. ''Drive to the conditions.''

Police said they were not releasing the man's identity at this time.

He is the fifth person to die on ACT roads this year and the third in March.

The fatal crash was one of eight accidents on Wednesday, resulting in a number of road closures.

The ACT received almost constant drizzle on Wednesday, with about five millimetres falling by 9 o'clock last night.

Rain caused a number of other accidents, including a two-car collision in Majura that affected traffic in the area.

There were two accidents in Tuggeranong, three in the city, two in Belconnen and one each in Weston Creek, Spence, Fychwick and Queanbeyan. The collisions began at 8am Wednesday and the last was reported about 6.30am on Thursday, with a single-car crash on Kuringa Drive in Spence.

A spokesman for the ACT Emergency Services Agency said there were no serious injuries in the other accidents across Canberra.