North Dakota’s positive test rate has averaged 30% over the past seven days compared with 6% the prior week. The positivity rate has risen to 26% in South Dakota, up from 17% the previous week, according to the analysis using testing data from The COVID Tracking Project.

Minnesota and Montana are averaging 7% of tests coming back positive, but Montana’s positivity rate rose on Sunday to 20%, according to the analysis.

The World Health Organization considers rates above 5% concerning because it suggests there are more cases in the community that have not yet been uncovered.