Cases are down in every region – the South, in the Mid-Atlantic, most of New England, the Midwest, the West. Some of the states hit hardest in the delta wave – Florida, Georgia, Hawaii, South Carolina and Tennessee – are reporting cases at a rate about one-sixth of where they were less than two months ago. Arkansas and Louisiana cases have fallen by more than three-quarters since then, too. But there are some warning signs from states, mostly in colder climates and often with low vaccination rates in some communities. Compared to the week of Sept. 4, the pace of new cases is up about 85% in Alaska, 63% in Michigan and 56% in Montana. They're even up 39% in Vermont, which was an early leader in vaccination. The U.S. has seen sharp declines in the past, only to see cases rise again. Winter could drive social gatherings indoors, where infections can spread more easily. So while this is a reason to celebrate, caution is still necessary and encouraged.