Although performance had improved when comparing July to August’s 71.9 per cent, it then dropped to 66 per cent for September.
Both are well below an NHS target of 95 per cent.
Fewer patients visited A and E at Barnsley last month - and attendances were lower than over the same period last year, figures reveal.
NHS England statistics show 8,269 patients visited in September - a drop of one per cent on the 8,324 visits recorded during August - and seven per cent lower than the 8,872 seen in September 2021.
Attendances were above the levels seen two years ago - in September 2020, there were 7,605 visits to A and E.
A total of 440 patients waited longer than four hours, and one person was delayed for more than 12 hours.
A Barnsley Hospital report said: “Trust performance remains extremely variable and is 33rd out of 109 in England.
“Ambulance handover performance remains below the national objective of 95 per cent of handovers within 30 minutes.
“However, performance did improve over the previous month to 70.4 per cent of ambulances turned around.”
NHS membership organisation NHS Providers said long waits in A and E are a ‘symptom of massive pressure right across the health and care system’.
A spokesperson from NHS Digital added: “The median time to treatment was 84 minutes.
“The median average is used to ensure figures are not skewed by particularly long or short waiting times.
“Around seven per cent of patients left before being treated.
“NHS staff have been working incredibly hard to bust the Covid backlogs and have treated more than 15 million patients in the last year.
“Our community diagnostic centres have delivered over 1.5 million additional checks since July 2021, and the number of people waiting more than two years for treatment has dropped by more than 80 per cent since February.”
Critics had cited some doctors’ alleged reluctance to see people in-person at GP surgeries due to the pandemic, while those who have been unable to secure a face-to-face appointment instead turned to the A and E department, forcing a knock-on impact on its response times.
Over the 12 years of Conservative government, public satisfaction with services has fallen from 77 per cent in Labour’s last year in government, to just 38 per cent now, the lowest level since the survey began in 1983, according to Barnsley East MP Stephanie Peacock.
“The government has admitted it is failing to meet its manifesto pledge to recruit more GPs,” she added.
“Under the Conservatives, the number of GPs is falling and hundreds of practices have closed since the 2019 general election.
“As a result, many ‘GP appointments’ held today are not with a GP.
“We need more GPs here in Barnsley and across the country.
“A Labour government will give the NHS what it needs to see people on time, as opposed to the Conservative government that consistently over promises and under delivers.”