A 70-year-old man is in serious condition after he and his dog became trapped when a gum tree crushed his ute north-east of South Australia.

The tree fell on top of the ute as the man was driving on Warren Road in Williamstown about 11.30am today. 

Emergency services arrived at the scene and worked to remove the tree with the help of members of the public, who were equipped with a grader and chainsaws.

They were able to free the man and his dog. 

The man was taken to hospital in serious condition while the dog escaped injury and is being looked after.

Emergency services then worked to clear the road as the ute was towed from the scene.

A cold front has brought strong to damaging winds across parts of the state today, prompting a severe weather warning from the Bureau of Meteorology.

Williamstown has felt gusts of up to 87 km/h today, with temperatures sitting around a chilly eight degrees.

Peak gusts of about 102km/h were recorded at Cape Willoughby, 98 km/h at Edithburgh, 96km/h at Outer Harbor Tide Gauge and 94 km/h at Minlaton Airport.