The current infection rate in Barnsley is 438.2 per 100,000 residents, with more than 1,000 cases recorded in the last seven days.
Public health boss Julia Burrows told the Chronicle: “Covid-19 cases continue to rise nationally, and Barnsley is seeing a climb in all ages, including the old and most vulnerable.
“We expect this climb to continue for at least three to four weeks.
“We can attribute the rise in cases to schools reopening and the associated increase in lateral flow testing, along with increased social mixing among people of all ages, following the lifting of restrictions.
“We need to work together to minimise community transmission, to keep our most vulnerable residents safe and avoid disruption, illness and death as a result of this virus.”