Data from Public Health England, published by Northumberland County Council, reveals the county-wide infection rate was 230.1 per 100,000 on November 22.
This compares to 280.7 on November 16.
There were 737 confirmed positive cases in the seven days up to November 22 compared with 899 in the week up to November 16.
The Government is preparing to introduce a new three-tier system of restrictions when lockdown ends on December 2.
Here are the 25 council wards in Northumberland with the highest figures.