THE SPREAD OF COVID-19 in Massachusetts appears to be accelerating, with the number of communities considered moderate or high-risk jumping by 40 percent and the state as a whole moving into the moderate risk category.

Gov. Charlie Baker released a breakdown by municipality on Tuesday that indicated four of the state’s 351 cities and towns were high risk and 29 were moderate risk. That information was based on the two-week period ending August 5.

On Wednesday evening, the Department of Public Health issued new municipal data based on the two-week period ending August 8. That new breakdown indicates the number of communities at high-risk had jumped from 4 to 11 and the number of communities considered moderate risk increased from 29 to 35. The state as a whole jumped from low risk to moderate risk.

The rankings are important as a barometer for COVID-19 in Massachusetts, but they have also taken on additional importance this week because the Baker administration is urging communities in the low-risk categories to send their children to school for in-person learning this fall. Communities are trying to decide between in-person and remote learning, or some hybrid combination of the two, by this Friday. The fast-changing information is making those decisions even more difficult.

The rankings are based on COVID-19 cases per 100,000 people, a new metric that Baker said more accurately captures the spread of the disease. Baker assigned colors to the different risk levels – red for high risk (more than 8 cases per 100,000 people), yellow for moderate risk (4 to 8 cases per 100,000), green (less than 4 cases per 100,000), and white (less than 5 cases overall).

On Tuesday, when Baker unveiled the new color-coded metric, only four communities – Lynn, Chelsea, Revere, and Everett – were red. By Wednesday evening, there were 11 red communities, with the addition of Saugus, Holyoke, Lawrence, Salem, Fall River, Granby, and Hull. Lynn had the highest rate among the red communities – 24 cases per 100,000 people. Hull had the lowest rate among the red communities, at 8 per 100,000.

The moderate risk, or yellow, communities numbered 29 on Tuesday. Two of those communities – Auburn and Belchertown – retreated into the lower-risk category by Wednesday and seven moved from yellow to red. Still, the yellow category grew on Wednesday to 35 with the addition of Bedford, Blackstone, Canton, Easthampton, Medford, Millbury, New Bedford, Northbridge, Rehoboth, Seekonk, South Hadley, Spencer, Stoughton, Sutton, and Topsfield.

The other 20 communities in the yellow category, including Boston, Brockton, Worcester, Springfield, Framingham, Quincy, Taunton, Peabody, Longmeadow, Middleton, Wrentham, and others, did not change. For a town-by-town breakdown for the entire state, click here.

Public health officials said the state as a whole had 3.2 cases of COVID-19 per 100,000 people in the initial report, but the number rose to 4.01 in the second report, just over the line into the moderate risk category.