More than 50 schools will be closed across Adelaide on Monday because of ongoing blackouts and storm damage.
Some 65,000 homes and businesses remain without electricity after Saturday’s wild storms, with SA Power Networks saying many will not be reconnected until at least Tuesday.
The Education Department said further reports of storm damage to schools might only come once the working week began.
It said arrangements were being made for students who were sitting their final exams.
The list of affected public schools include preschools, primary and high schools across the state.
The department said individual schools would continue to provide updates to parents and their communities.
There were 423,000 lightning strikes recorded on Saturday, along with winds of 106 kilometres per hour, according to SA Power Networks.
It says power was cut to 160,000 customers, with 310 outages reported across the state, from the far west through to the eastern border with New South Wales and Victoria, and nearly 500 reports of wires down.
SA Power Networks's Paul Roberts said people should plan for an extended power outage and consider staying with family or friends where necessary.
"We won't be able to provide accurate estimates of power restoration times until crews get to the site and are able to make an assessment of the cause and the work needed to restore power," he said.
Mr Roberts said rebuilding and repairing the network and restoring power would "continue into Tuesday and possibly beyond".
"This is the largest outage event we have had since the statewide blackout in 2016," he said.
Authorities have encouraged South Australians to turn off their solar panels "as a last resort" to help stabilise the energy grid.
The Australian Electricity Market Operator (AEMO) said South Australia had been disconnected from the National Electricity Market due to a fallen transmission tower.
It said the transmission network "remains in a secure operating state".
Business owners have been assessing the damage, but many have been hampered by the lack of power.
Alan Pan, a supermarket owner in Adelaide's southern suburbs, said he would have to throw out most of the dairy and meat products at his store due to the power outage.
"Everything needs to be chucked out," he said.
"We will have staff waiting outside the shop this morning, waiting for it to be opened and unfortunately I have to send everyone home."
State Duty Officer Robert Charlton said the State Emergency Service (SES) had been called out to about 1,000 jobs in 24 hours.
Mr Charlton said the majority of work involved fallen trees and power lines, and volunteers hoped to clear the majority of storm damage by the end of Sunday.
He said the Adelaide Hills and southern suburbs were the hardest hit by the storms.
"We saw quite a spread across metro and some rural areas, but predominantly they were around the southern suburbs," he said.
The CFS door-knocked in the Adelaide Hills on Sunday to check residents' safety after multiple properties in the area were damaged by fallen trees.
Upper Sturt resident Dotty Telford said she narrowly escaped being hit by a fallen tree.
"I was just driving up the road 30 seconds before these big trees came down," she said.
"I just pulled into my driveway, I grabbed my groceries there and then a massive crash."
Stewart Bishop said his B-double truck was stuck early on Sunday morning due to downed powerlines on Portrush Road in Adelaide's eastern suburbs.
He said the truck could not get through backstreets, and he was forced to wait before eventually being able to turn.
"We have a heap of trucks coming up behind us and most of us are going interstate," he said.
"It's going to hold up everything."
In Adelaide's north, police rescued nine fishermen on Sunday morning who were stranded on a breakwater.
SA Police said the men had walked out to the breakwater at St Kilda earlier, only to be cut off by a rising tide and strong winds.
Water Operations Police ferried the men to dry ground, and then went back to collect their gear.
Police said the men were checked over by paramedics but required no treatment.
Meanwhile, police have warned drivers to avoid areas taped-off by emergency services.
SA Police said a 54-year-old man drove through SES tape at Flinders Park on Saturday and became entangled with a fallen tree and power lines.
Police attended and warned the man to remain in his car due to the live power lines caught on his vehicle.
He was safely extracted from the scene after SA Power Networks rendered the power lines safe, and was later fined by police.
