Otago and Southland recorded a combined 1238 new cases, up on the previous daily record of 918 last Thursday.
Another person also died in the region, a man older than 70.
Neither the Southern District Health Board nor the Ministry of Health gave any further details.
Case numbers are usually high on Tuesdays as many people wait until after the weekend to get a test but there could be other reasons for the surge, such as new sections of the population now contracting Covid, University of Canterbury statistician Prof Michael Plank said.
"We have been seeing very high case numbers in young age groups and lower rates in older age groups ... but we are starting to see signs that it is shifting a little toward older people."
Ministry statistics show a third of southern Covid-19 cases are in people aged 20-29, but infection rates for people aged 30-49 have steadily increased, and that age group now covers 22% of the region’s cases.
Almost 7% are children aged under 10, but less than 5% of cases are in people aged 60 or older.
Among those in the South who recorded a positive test yesterday were Taieri MP Ingrid Leary and Dunedin Mayor Aaron Hawkins.
Of the 1238 new cases, 409 were in Dunedin, 270 in Queenstown-Lakes, 185 in Invercargill and 100 in Waitaki.
Fourteen southerners were in hospital, 11 in Dunedin and three in Southland.
Ms Leary spent several hours with Prime Minister Jacinda Ardern last Thursday when she was in Dunedin: Mr Hawkins did not see Ms Ardern during her visit as he was in isolation as a close contact of an earlier case.
A spokeswoman for Ms Ardern said she was in good health.
Prof Plank said most parts of New Zealand could expect to experience their regional peak of the pandemic in the next week or so.
"Down here in the South we are definitely behind the curve, certainly behind Auckland and definitely behind most of the North Island, simply because we were a bit late to get going.
"I wouldn’t think it would go above 1500, so hopefully we will see a peak at around that level in the next week or so."
Yesterday, director-general of health Dr Ashley Bloomfield said Covid cases in the most-affected region, Auckland, were now on the decline, but at their peak had exceeded modellers’ predictions, although hospitalisations had been as expected.
Prof Plank said across the rest of the country, including Otago and Southland, the Omicron wave had behaved closer to modelling predictions.
The Canterbury DHB has recently closed some of its vaccination centres and opted to "re-orientate" its programme.
Southern vaccine roll-out programme lead Karl Metzler said the SDHB had no similar plans and the two mass vaccination clinics in Dunedin and Invercargill would continue to operate.
As demand for Covid vaccinations waned, the centres would begin to also offer other vaccinations, Mr Metzler said.
"This will remove pressure from primary care and help bolster Southern’s childhood immunisation rates and influenza immunisation uptake for the coming flu season."
Nationally, 21,616 new community cases of Covid were reported by the Ministry of Health yesterday.
Dr Bloomfield said 960 people were in hospital with Covid-19, 22 of whom were in intensive care.
