COLUMBUS (WCMH) – By two metrics, Ohio’s COVID-19 cases are at their highest point of the summer so far.

The Ohio Department of Health on Monday reported 660 new coronavirus cases, the highest one-day total since May 28, which also saw 660. And last week, ODH reported 2,842 cases, the most in a Monday-Sunday period since 4,634 cases May 24-30.

These data points are the latest in a July bump in cases that NBC4 reported on Friday. After enjoying a steady decline since April, cases have increased over the past two weeks.

With 660 new cases, Monday became the sixth day this month – and the fifth day in the last six – to see more than 400 cases. June saw four days over 400 cases, but all were early in the month.

Daily case counts are not backdated to the day of infection, but trends among these backdated “onset cases” tend to follow the raw releases. The last day Ohio saw more than 400 onset cases was June 2. But it was as recently as early- to mid-May when Ohio was recording multiple days with more than 1,000 onset cases.

Ohio’s rate of onset cases per 100,000 people over two weeks is 34.19 as of Friday, which is the highest it’s been since June 15, according to NBC4’s tracking. The rate has been increasing for the past two weeks after bottoming out at 23.21 per 100,000 on July 3.

Cases per county in July have mostly lined up with populations, with major counties like Franklin, Cuyahoga, Montgomery and Hamilton leading the state. But a notable outlier is 11th-ranked Lawrence County.

Despite being home to just under 60,000 people, the rural county at the south-central tip of Ohio has seen 100 coronavirus cases in July, 2.09% of the state’s total.

Health experts, though, are not yet ready to call this recent small bump in cases a lasting trend. ODH noted in its data release Monday that the 660 new cases “may be elevated due to a technical issue that prevented a small number of cases from being counted over the past several weeks.” That issue, ODH says, has been resolved.

Still, the federal Centers for Disease Control and Prevention said Monday that COVID-19 cases are rising in all 50 states for the first time since January, driven by the more contagious Delta variant of the virus, which has also gained a foothold in Ohio.

Delta made up 15% of cases sequenced by ODH from June 6-19, the latest results available, Chief Medical Officer Dr. Bruce Vanderhoff told reporters last week. In the two weeks before that sequencing, Delta was only 1.9% of Ohio’s cases.

“It appears that communities with low vaccination rates,” Vanderhoff said, “are at particular risk of what have been called ‘hyper local outbreaks,’ concentrating the devastating impact of this disease in those communities.”

Butler County, in suburban Cincinnati, was listed as a COVID-19 hotspot this month by the CDC but is considered to be recovering.

5,666,991 people have at least started vaccination in Ohio as of Monday, according to ODH. More than 48% of the state. That ranks in the bottom third of U.S. states. More than 45% of Ohioans have completed vaccination.

“The reality is we now have two Ohios,” Vanderhoff said, “an Ohio that is vaccinated and protected on the one hand, and an Ohio that is unvaccinated and vulnerable to Delta on the other.”